grab the evga precision tool from the site if they let you (they have been gay about registering lately) or if not let a teammate know and it will happen....
For gpu mods..... pny seems kinda weak on gpu's from my experience, but you may get lucky. the gtx 260 has vmods, but it really depends on the pcb how easy thay are. some a pencil mod works fine, others require hardcore soldering.
Supply the heads here with the exact model from the stickers and if you can a pic of the circuit board (back side) and I'm sure they will hook you up with what you need. If not I will do some digging and find a place that has a definitive mod for thoser things.
but start with evga precision.. you will like the results