Well, I know they changed the set up shortly after I tinkered with mine, but it looks like everything is fairly similar, just laid out differently. Skip the first page by clicking the "customize" button then on the sidebar click "Custom CSS"

Since it should have custom CSS, I would think the only thing you'd have to do is insert the new header URL in the place of the old one. If it's not the exact same size, it may look a bit odd though.

Email me if you need help. ;)