I suggest a vf-900 if you want somthing really quiet.
There will just be some screws on the back of the card that you take off. All you will need to do is use some is take off the thermal pad with somthing(credit cards work good) and then use 99% isopropyl alcohol to get any remaining off. You dont need 99% but it works the best, I use 91%. Then just apply the new thermal paste and follow the instructions on how to install the new heatsink. It is really pretty easy.