Forumlar / Cotonti / Support / Forum Width

This is the file structure of GamePortal skin:

admin/

images/

img/

js/

plugins/

comments.tpl

footer.tpl

forums.editpost.tpl

forums.newtopic.tpl

forums.posts.tpl

forums.sections.tpl

forums.topics.tpl

gameportal.css

gameportal.en.lang.php

gameportal.nl.lang.php

gameportal.php

gameportal.README-HELP.txt

header.tpl

index.tpl

karma.tpl

list.group.tpl

list.tpl

message.tpl

page.add.tpl

page.edit.tpl

page.tpl

pfs.tpl

pfs.view.tpl

plugin.tpl

pm.list.tpl

pm.send.tpl

pm.tpl

polls.tpl

popup.tpl

ratings.tpl

users.auth.tpl

users.details.tpl

users.edit.tpl

users.profile.tpl

users.register.tpl

users.tpl

All I want to do is make the forum full width instead of having the forum fill only 75% of the screen due to the sidebar.  I cannot find anything in the .tpl files to help me achieve this goal.  There is no config.php.