OK well actually I have somewhat figured it out. I reallized I was modifying the wrong file.
The file to modify is:
plugins->buddypress->bp-themes->bp-default->header.php
and
plugins->buddypress->bp-themes->bp-default->forums->index.php
in header.php:
change
title="<?php _e( 'Forums', 'buddypress' ) ?>"><?php _e( 'Forums', 'buddypress' ) ?></a>
to
title="<?php _e( 'Forums', 'buddypress' ) ?>"><?php //_e( 'Forums', 'buddypress' ) ?>Group Topics</a>
and in index.php change:
<h3><?php _e( 'Group Forums Directory', 'buddypress' ) ?>
to
<h3><?php //_e( 'Group Forums Directory', 'buddypress' ) ?>Group Topics Directory
The links and everything is still the same. but in the navigation bar you now see “Group Topics” instead of “Forums” and in the Forums page, you see the title as “Group Topics Directory” instead of “Group Forums Directory”.
If anyone else can do this using a plug-in or if anyone else has any other ideas, please let me know, thank you.