I saw this paper not too long ago, a lot of good information.
Needless to say, I've tried to recreate their repair methods the best I can, with pretty good results.
Tools:
Electric stove
Heat gun or hot air reflow station
Infrared thermometer (you can usually find them for $60 or so at hobby shops that sell nitro powered R/C cars)
I put the motherboard on metal standoffs to hold it about 1/2 inch above the heating element, with the stove on a low setting, I tweaked it with the infrared thermometer until the motherboard was about 150-170*C (in the paper they said to heat the underside of the board to 165*C)
Then, I added some liquid flux to the edges of the CPU and GPU, and while keeping the stove on, proceeded to heat the GPU and then the CPU to 220-240*C with a Hakko reflow station (measuring at different points on the package, the key here is to get it over 218*C, the melting point of lead-free solder.) Don't hold these high temps for too long though (max 20 seconds of so) or you risk damaging the board. Then remove the heatgun, turn off the stove, and let the board cool off. Leave the board on top of the stove though, the residual heat from the stove will allow the board to cool down slowly.
I havent been able to do any long term testing yet, but the 0020 board I've had laying around forever fired right up (with the stock x-clamps), IMO it is the best possible way to reflow the board without spending thousands, again the key here is to be able to accurately measure the motherboard and die temp