I recommend that you download the latest stable tagged version from the releases section here: https://github.com/glowlogix/wp-frontend-profile/releases

Once you have downloaded the plugin you need to add it to your WordPress sites plugins folder, usually found in wp-content/plugins and then activate the plugin through the Plugins menu in the WordPress dashboard.

Once this is done you should use the template function name wpfep_show_profile in any of your themes template files in order to output the front end profile editor like so:

<?php echo wpfep_show_profile(); ?>