Add the post-count-plus.php file to bbPress my-plugins/ directory and activate.
You do not need to edit any template (theme) pages for any of the features.
Admin menu is under Site Management -> Post Count Plus
and offers many, many options to control how the user info appears next to posts.
For advanced users, you can get post count and other info displayed in
any template by using direct calls, ie. <?php post_count_plus($user->ID); ?>