MyBB Community Forums

How would I go about adding this to a mybb theme? http://gyazo.com/d13121e14a8144a1865da7c6aed04efb . I have the general idea of how to do it, like float sidebar and the container and stuff left.  But I need to know how to achieve that look.

Well, that is a custom job, custom css, if you know the website, just look at their code and see how it is done using firebug.

I know how to do it by normal means, just not with mybb. I would have to know the div that incorporates everything so the I can make it float left so the sidebar would stay left. Just don't know how to incorporate everything.