Apply a little poop of MX-2. Disassemble a video card is ( for me i think ) way easyer compare to set up an entire pc. Remove screw and get everything off like removing a CPU cooler on a backplate well. then use the way you want to apply this smoochie thermal cream

miam

and stick the cooler where it belong. If nothing do then get a water cooling loop or ( has I recomend ) go see with Arctic Cooling what they haev for GTX 260.
Arctic Cooling Arctic Cooling
This cooler is pretty imprssive, have already mount many on card and wow result are amazing for the buck.
Ask for more if ever needed.