Actually the component take advantage of Joomla! Media Manager, and it just expands it's capabilities by giving you the ability to add any file within your articles.
Please check Joomla! Help for how to use: https://help.joomla.org/proxy/index.php?option=com_help&keyref=Help34:Content_Media_Manager
One important notice is that the documents you upload and use are not somehow protected. They are treated exactly the same way as your images.
If you need protection on your files with Joomla! ACL you should not use this component.