Here you go: ajax-register-form.php, located in the child theme directory.

<!--title-->

<div class="bpajax-register-window">
	<div class="bpajax-register-title">
		<span class="topmodaltext2"><?php _e( 'Register for full site access', 'bp-ajax-registration' ) ?></span>
	</div>
	<!--form wrap-->
	<div class='register_form_wrap'>
		<form action="" name="signup_form" id="register_form" class="" method="post" enctype="multipart/form-data">

			<?php do_action( 'template_notices' ) ?>
			<?php if ( 'request-details' == bp_get_current_signup_step() ) : ?>
				<?php do_action( 'bp_before_account_details_fields' ) ?>

                <p style="font-size: 18px; color: black;">You must be an IHC member in good standing for full site access.&nbsp;&nbsp;Not yet an IHC member?&nbsp;  Download a membership form <a href="https://wp.interiorhorsecouncil.com/wp-content/uploads/2017-Membership-Form-full.pdf" target="_blank" rel="noopener noreferrer">here</a>.&nbsp;  <br><br>All fields are required except alternate phone.</p>

				<div class="register-section">

					<?php /***** Basic Account Details ******/ ?>

					<label	for="signup_username">
					    <?php _e( 'Username', 'bp-ajax-registration' ) ?>
                        <?php _e( '*', 'bp-ajax-registration' ) ?>
                    </label>
					<?php do_action( 'bp_signup_username_errors' ) ?>
					<input type="text" name="signup_username" id="signup_username" placeholder="Username"value="<?php bp_signup_username_value() ?>"/>

					<label	for="signup_email"><?php _e( 'Email Address', 'bp-ajax-registration' ) ?><?php _e( '*', 'bp-ajax-registration' ) ?></label>
					<?php do_action( 'bp_signup_email_errors' ) ?>
					<input type="text" name="signup_email" id="signup_email" placeholder="Your email address"value="<?php bp_signup_email_value() ?>"/>

					<label for="signup_password"><?php _e( 'Choose a Password', 'bp-ajax-registration' ) ?><?php _e( '*', 'bp-ajax-registration' ) ?></label>
					<?php do_action( 'bp_signup_password_errors' ) ?>
					<input type="password" name="signup_password" id="signup_password" placeholder="********" value=""/>

					<label for="signup_password_confirm"><?php _e( 'Confirm Password', 'bp-ajax-registration' ) ?><?php _e( '*', 'bp-ajax-registration' ) ?></label>
					<?php do_action( 'bp_signup_password_confirm_errors' ) ?>
					<input type="password" name="signup_password_confirm" id="signup_password_confirm" placeholder="********" value=""/>

                <!-- #basic-details-section -->

				<?php do_action( 'bp_after_account_details_fields' ) ?>
				<?php /***** Extra Profile Details ******/ ?>

				<?php if ( bp_is_active( 'xprofile' ) ) : ?>

					<?php do_action( 'bp_before_signup_profile_fields' ) ?>

					<?php /* Use the profile field loop to render input fields for the 'base' profile field group */ ?>
						<?php if ( bp_is_active( 'xprofile' ) ) :
							if ( bp_has_profile( apply_filters( 'bpajaxr_xprofile_args', 'profile_group_id=1&hide_empty_fields=0&hide_empty_groups=0' ) ) ) :
								while ( bp_profile_groups() ) : bp_the_profile_group();
									?>

									<?php while ( bp_profile_fields() ) : bp_the_profile_field(); ?>

										<div class="editfield">

											<?php
											$field_type = bp_xprofile_create_field_type( bp_get_the_profile_field_type() );
											$field_type->edit_field_html();
											?>

											<?php do_action( 'bp_custom_profile_edit_fields' ) ?>
											<?php do_action( 'bp_custom_profile_edit_fields_pre_visibility' ) ?>

											<p class="description"><?php bp_the_profile_field_description() ?></p>

										</div>

									<?php endwhile; ?>
									<?php $fields_ids[] = bp_get_the_profile_group_field_ids();//COLLECT FIELD IDS?>

								<?php endwhile; endif; endif; ?>
						<input type="hidden" name="signup_profile_field_ids" id="signup_profile_field_ids" value="<?php echo implode( ",", $fields_ids ); ?>"/>

					</div><!-- #profile-details-section ends here -->

					<?php do_action( 'bp_after_signup_profile_fields' ) ?>

				<?php endif; ?>

				<?php if ( bp_get_blog_signup_allowed() ) : ?>
					<?php do_action( 'bp_before_blog_details_fields' ) ?>
					<?php /***** Blog Creation Details ******/ ?>

					<div class="register-section" id="blog-details-section">
						<h4><?php _e( 'Do you need a blog?', 'bp-ajax-registration' ) ?></h4>
						<p>
							<input type="checkbox" name="signup_with_blog" class="signup_with_blog" id="signup_with_blog" value="1"<?php if ( (int) bp_get_signup_with_blog_value() ) : ?> checked="checked"<?php endif; ?> /> <?php _e( 'Yes, I\'d like to create a new site', 'bp-ajax-registration' ) ?>
						</p>

						<div id="blog-details"
						     <?php if ( (int) bp_get_signup_with_blog_value() ) : ?>class="show"<?php endif; ?>>

							<label for="signup_blog_url"><?php _e( 'Blog URL', 'bp-ajax-registration' ) ?><?php _e( '*', 'bp-ajax-registration' ) ?></label>
							<?php do_action( 'bp_signup_blog_url_errors' ) ?>

							<?php if ( is_subdomain_install() ) : ?>
								http:// <input type="text" name="signup_blog_url" id="signup_blog_url" value="<?php bp_signup_blog_url_value() ?>"/> .<?php echo preg_replace( '|^https?://(?:www\.)|', '', network_site_url() ) ?>
							<?php else : ?>
								<?php echo network_site_url() ?>/ <input type="text" name="signup_blog_url" id="signup_blog_url" value="<?php bp_signup_blog_url_value() ?>"/>
							<?php endif; ?>

							<label for="signup_blog_title"><?php _e( 'Site Title', 'bp-ajax-registration' ) ?><?php _e( '*', 'bp-ajax-registration' ) ?></label>
							<?php do_action( 'bp_signup_blog_title_errors' ) ?>
							<input type="text" name="signup_blog_title" id="signup_blog_title" value="<?php bp_signup_blog_title_value() ?>"/>

							<span class="label"><?php _e( 'I would like my site to appear in search engines, and in public listings around this network.', 'bp-ajax-registration' ) ?>
								:</span>
							<?php do_action( 'bp_signup_blog_privacy_errors' ) ?>

							<label><input type="radio" name="signup_blog_privacy" id="signup_blog_privacy_public" value="public"<?php if ( 'public' == bp_get_signup_blog_privacy_value() || ! bp_get_signup_blog_privacy_value() ) : ?> checked="checked"<?php endif; ?> /> <?php _e( 'Yes', 'bp-ajax-registration' ) ?>
							</label>
							<label><input type="radio" name="signup_blog_privacy" id="signup_blog_privacy_private" value="private"<?php if ( 'private' == bp_get_signup_blog_privacy_value() ) : ?> checked="checked"<?php endif; ?> /> <?php _e( 'No', 'bp-ajax-registration' ) ?>
							</label>

						</div>

					</div><!-- #blog-details-section -->

					<?php do_action( 'bp_after_blog_details_fields' ) ?>

				<?php endif; ?>

				<?php do_action( 'bp_before_registration_submit_buttons' ) ?>

                <!--  checkbox & registration button have to be siblings
                      in order for css hide & show to work on registration button
                -->
                <div class="submit">
                <input type="checkbox" id="terms-privacy" class="terms-privacy" /> I have read and agree to the <a class="IHC_agree popup-terms" style="color: #425e8c; cursor: pointer;" href="#">IHC terms & conditions</a> and <a class="IHC_agree popup-privacy" style="color: #425e8c; cursor: pointer;" href="#">IHC privacy policy</a>.

<!--				  -->
					<input type="submit" name="signup_submit" id="signup_submit" class="hide-check btn btn-default"value="<?php _e( 'Register', 'bp-ajax-registration' ) ?>"/>
<!--				</div>   -->
                </div>
				<?php do_action( 'bp_after_registration_submit_buttons' ) ?>
				<?php wp_nonce_field( 'bp_new_signup' ) ?>
			<?php endif; // request-details signup step ?>
		</form>

		<?php if ( 'completed-confirmation' == bp_get_current_signup_step() ) : ?>

			<h3><?php _e( 'Sign Up Complete!', 'bp-ajax-registration' ) ?></h3>

			<?php do_action( 'template_notices' ) ?>
			<?php do_action( 'bp_before_registration_confirmed' ) ?>
			<?php if ( bp_account_was_activated() ) : ?>

				<h3><?php _e( 'Account is now pending approval.', 'bp-ajax-registration' ) ?></h3>

                <!-- log the user out, my customization -->
                <!-- Will want a logout redirection -->
                <?php wp_logout(); ?>

				<p> <?php _e( 'Thank you for joining our Community!', 'bp-ajax-registration' ); ?></p>

			<?php else : // completed-confirmation signup step ?>
				<?php if ( bp_registration_needs_activation() ) : ?>
					<p><?php _e( 'You have successfully created your account! To begin using this site you will need to activate your account via the email we have just sent to your address.', 'bp-ajax-registration' ) ?></p>
				<?php else : ?>
					<p><?php _e( 'You have successfully created your account! Please log in using the username and password you have just created.', 'bp-ajax-registration' ) ?></p>
				<?php endif; ?>

				<?php do_action( 'bp_after_registration_confirmed' ) ?>
			<?php endif; ?>
		<?php endif; // completed-confirmation signup step ?>

		<?php do_action( 'bp_custom_signup_steps' ) ?>
		<div class="clear">
		</div>

	</div>
</div>