Use Disqus comments as an alternative to your WordPress comments or together with them.
The plugin is available for free in wordpress.org repository. You can download it
or install directly from the WP Dashboard › Plugins › Add new panel.
Like all other plugins from wordpress.org site, when a new version of the plugin is available, you will be notified about it directly in your WP Dashboard.
The plugin will require you to obtain API keys and paste them into the settings. Please use the following tutorial to configure the plugin.
Disqus Comments Tab
To activate the Disqus tab on a single post (screen on top), just install and activate the plugin.
By default, Disqus Comments are shown in tabs next to the normal WordPress comments. To disable the WordPress comments system and use only Facebook, please read this.