How to replace my theme’s entire comment system?

Try downloading a copy of the iNove theme and see what you can re-use in your own theme.

I have both themes. Are you suggesting that I just find everything in the inove things that have to do with comments and place it in the Modxblog theme?

Sort of – but you’re unlikely to be able to do a straight swap from one theme to another. You’ll need to effectively dissect the comments in the iNove theme (both the template files and the CSS) and transfer them – bit-by bit – into your theme making adjustments where necessary.

It’s not working because all that the inove theme says in the comments.php file is:

<?php
if (function_exists(‘wp_list_comments’)) {
comments_template(”, true);
} else {
comments_template();
}
?>