first of all -> THANK YOU iFIXIT!
my xbox died on me 3 days before the MW3 release. 3 red lights! what a timing.
i followed the guide and did everything slow and careful as instructed. (didnt do the reflow.)
the thermal paste thing was a bit tricky wasnt really sure how much i
have to put on the CPU and GPU to provide the right cooling but after
assembling all back together and hitting the "on" button the green lights came on!
haven't tried to play a longer session but i definetly will do this weekend with MW3.