Wrong section to post this in - but in the admincp goto "Forum Manager" click on the forum you want to change the skin on, look for "Style Options" and there you go
thanks alot. if i just wanted to change the header for each forum, does it makes sense to duplicate the skin for every forum just to change the header?
Honestly? Not really, it will add a bit of overhead. What area do you consider the header, where the logo is? I can offer some solutions once I find this out.