Integrate Punbb into my site

Ok what i want to do is to integrate punbb into my website. So i have my logo and the main design on the site but with the punbb forum in the content.. Like this example

Main site: http://www.lrguild.org
Forum: http://www.lrguild.org/forum/

I've tryed everything that i can come up with but i just can't figure it out. Please help me out.