• Download the plugin
  • unzip it
  • upload bp-members-with-uploaded-avatars folder to wp-content/plugins
  • Visit Dashboard->Plugin->Installed plugin and activate the plugin
  • Now go to Dashboard->Appearance->Widgets and add the Members with Uploaded Avatar widget to your theme's Widgetized area.
  • that's it.

Alternatively, use the WordPress plugin installer. Upload the plugin and activate it.