the footer can be edited to give way to sitewide link exchange or just dedicate a page there where you can install an automated link exchange script on it just like linkman which is an automated link exchange script http://www.phpjunkyard.com/php-link-manager.php
so you don't have to edit footer everytime someone wants to link exchange with you very risky (one wrong character there your phpbb won't run) and before doing any modifications backup first.
I'd also like to stress backing up your site, before any modification, style change, or code edit. Backup all files that you will work with so that you have a revert point. Also, backup your site at least once a week minimally. Mor often if possible. I try to do it daily. you can hit backup and go to sleep but backups have saved me a few times. If you're looking to edit the footer page it's overall_footer.tpl in w/e theme you want to edit it in. HEader is overall_header.tpl, be sure to use comment tags so that you will remember what you did at a later date!
__________________
█ wuproxy.com - Free proxy service that's fast and reliable
DNKitchen.com and Chef Patrick ---> 
Simplicity and Superiority. 
