Print this image out (step 13) - trust me, you'll need it later!
Wow that took a long time. Almost 2 hours! Fair enough, I've never done it before, and it was for a colleague so I was being extra careful!
As long as you take your time and remember which screw is which, it's fairly straightforward if time consuming. I'd recommend printing the image out in step 13 - some of the screws are incredibly similar. It will help you with which is which when you come to put it back together.
The guys at ifixit are brilliant! I couldn't have done it without this guide!