7800GT Volt-modhardnrg -
The success of this mod really relies on your skills and confidence with a soldering iron. I use a 50W variable iron with a tip tapered much like a pencil.
Tip: Use a fine-tip soldering iron bit
Even for someone with soldering experience, this is possibly the most difficult soldering task, so if you are unsure about your ability then go practice on an old network card or something else with small surface-mounted components.
These three pictures show the locations of the solder points. The first is an overall view of all the points, the second is a close-up of the gpu points, and finally the third is a close-up of the memory points.