While no site to link you to at the moment, the process itself is very straight-forward. Basically, open up the case and look at the HSF assembly over the CPU. There should be a way to remove it by unfastening the HSF from the Mother Board via clips. Once the clips are detached, gently but firmly pull the HSF off the CPU; be sure to scrape off any residue of Thermal Paste. Open the CPU socket (there is only one way to do it) and remove the old CPU.
For installing the new one, again, there is only one way it can be installed. Line up the CPU with the Socket and gently place it in. Lock it into place and put a small amount of Thermal Paste on the CPU itself. Gently place the HSF on top and secure it.