[Plug-in: Comment Highlighter] How to Implement?

I’m working with the Fauna Theme.
Trying to use the Comment-Highlighter Plugin.

Does anyone know how to insert the code into this theme to get the plugin to work??? The theme has a different php for the comments. (has comments.php & template-comments.php – comments.php just calls the other file)

I tried to use the instruction on the plugin wiki page, but not successful.
link to plugin here
link to theme here

Please help!
It would be greatly appreciated.