First of all I'd try to return the card and get a 128MB version. 256 is a waste of money right now. Second, I wouldn't worry about the heatsink, if you're a n00b, just leave the thing alone, and especially no voltage modding on an expensive toy like that. I haven't even done any soldering/voltage mods on anything. Take your time and proceed cautiosly and you'll end up much happier than if you blindly go into things.