Hey Till,
You're a great friend to research for your buddy! We have a comprehensive guide of tech articles for anything and everything related to the 997. They're all step-by-step guides, so your friend shouldn't have an issue following along. I've included a link for your convenience! Btw, tell you buddy to sign up on the forum so we can see pictures of his beauty!
Porsche 911 Tech Articles -
Porsche 911 (1998-2012) Technical Articles - Porsche 996 & Porsche 997 - Pelican Parts
-Dmitry