First of all I would like to thank all the people involved on Xbox-scene, Llamma and other forums who have made this repair possible.
Disclaimer: Do not use this method if you have the warranty. Use this method as your last resort.
What is RRoD?
Basically, RRoD (Red Ring of Death) is a name given to Microsoft?s 3 Red light error and is a caused by cheap manufacturing.
How do you find out the reason causing RRoD on your Xbox 360?

Hold the Sync button and press the Eject button 4 times. You?ll find different number of quadrants of red lights illuminating. Using this you can make a code out of it. Here is the legend.
All four lights illuminate = 0
One Light = 1
Two Lights = 2
Three Lights = 3
Fixes as per the Codes:
1) Part 1
1RROD E73; E74;
2RROD 0011; 0012;
3RROD 0002; 0020; 0021; 0022; 0023; 0101; 0102; 0103; 0110; 0203
These errors can be fixed by X-Clamp replacement method. Click here for the tutorial.
2) Part 2
3RROD 0001, 0002
Click here for the tutorial.
After your fix, you can try the 12 Volt cooling mod. This ensure longer life of your fix.

I still think reballing, or at least properly reflowing The BGA (Ball Grid Array) components is one of the best ways to go about it. I pick up lead .6mm solder balls to do my dirty work... Take a crapped out 360 to practice on... I will post a video Tut soon, but you can google videos on it if you wanna try it without all the fancy equipment. I have never done a 12V cooling mod, but I have a unit that overheats in about ten minutes, and the fan speed never increases, I'm guessing this would be a nice way to go with that one.

IMO reballing is HARD work.....and you should have some experience to do it.