it seems unbelievable but I actually managed to revive two xbox 360 consoles from the RROD death
using these guides (attached as PDF) – it can be done!
so far I have refused to drill holes and replace the X-clamps with screws but I might do that in the future
just used fresh thermal compound and bent the x-clamps to clamp a bit tighter on that heatsink (eliminating any movement)
I did do the overheating part, just to torture the console a bit :P

the airflow guide is also something I will do tonight, can’t hurt :P
http://www.instructables.com/id/Fix-the-Red-Ring-of-Deathwithout-towels/

original instructions and opening guide:
http://www.llamma.com/xbox360/repair/xbox-360-repair.htm
http://www.llamma.com/xbox360/repair/ring_of_light_x-clamp_fix.htm
http://www.llamma.com/xbox360/repair/Xbox-360-Disassembly.htm