Oh, and it looks like it also says to re-upload these two files:
admin/includes/extra_definitions/testimonials_manager.php
admin/includes/languages/english/extra_definitions/testimonials_manager.php
However, saying to upload those two files isn't the same as saying to upload ONLY those two files, IMO. It's always best to err on the side of being more clear than assuming that someone will infer your meaning.