Easy to follow guide but I had a real problem that I hadn't even considered until I finished and started using the computer. After following the guide to the letter I checked everything was working then I stuck the screen back on. BUT when I came to plug the external drive back in.. DISASTER! The USB and thunderbird ports hadn't aligned in the case properly. They were only out by a millimeter, and there was nothing to suggest anything was misaligned when I putting everything back together, but It meant I couldn't plug anything into the rear ports. Strip down and start again..