Can I replace the brake light bulb on my audi a3 or do I need to take it to audi to do?

A brake light has gone on my audi a3 and I thought yep I'll just replace it but it's all panneled in. I have changed bulbs on Vw's with not hassle, just unclip the small panel and replace it but on the audi a3 it's all boxed in. How do I replace them?Can I replace the brake light bulb on my audi a3 or do I need to take it to audi to do?
The same as on the A4;

http://www.jmaguire.com/blog/2006/02/05/