Overriding the default templates


So in the templates for the directory plugin it says that I can override the templates in my theme. So I copied the files over to my theme so I could edit them and now I am getting fatal errors. The files are part of a class evidently. Here is the error:

Fatal error: Using $this when not in object context in /home/jetchart/public_html/wp-content/themes/minimum-jcb/page-update-listing.php on line 21

So my question is this, how do I override the templates in my theme without having to completely rework the class?