• Download The Current aversion from right side download Button
• Unzip the zipped file, you will get wp-s3-slider
• Upload Wp-S3-slider to wp-content/themes
• Login to dashboard
• Activate WordPress S3 slider from Plugins->Installed
• Go to Appearance->widget and add the widget.  Fill the options as you want
• That's it.
• Alternatively, you can use WordPress plugin Installer to Install the widget.