Can you add how to change forum themes? Its easy but even Prototype didn't know how to do it. This would be fine mate. Good tutorial.
Is a tutorial for such a simple thing really needed? We should have a page for small tutorials like this, there's no need for a topic for very small things like this.
Anyways here you go:
1. Click on Profile button
2. Hover on Modify Profile -> select Look and Layout.
3. You will find this text: "Current Theme:" , now click on Change in the same row, and select your preferred theme by clicking "Use This Theme".