first, be sure that your BIOS version will accept it (visit the mobo website to view compatibility). you may have to flash to a newer BIOS version
as for the physical installation...
1. unplug the power supply
2. use a ground strap or touch grounded metal before touching anything electronic
3. unplug the heatsink's fan plug from the mobo
4. unhook any retaining clips
5. gently rotate the heatsink back and forth to free it from the CPU (do not pull up or you might yank the CPU from the socket (heating the CPU first may make this process easier)
6. once you can rotate it easily, pull up at one corner, and the whole thing should pull off easily.
7. lift up the lever on the side of the socket to release the CPU
8. remove the old CPU
9. with the lever still up, install the new CPU (use the corner markings to line it up, it will only fit one way. it should just drop in.. DO NOT FORCE IT!)
10a. if the CPU came with a new heatsink, remove any protective film from the bottom and mount the heatsink on the CPU
10b. if you are reusing the old heatsink or would like better cooling on the new one. remove all traces of the old tape pr paste compound with isoproply alcohol. let it dry (a few seconds), and apply thermal compound (arctic silver 5 is the best available) different compounds have different application instructions so just foolw the instructions of the package or goto their website
11. attach any retaining clips
12. plug the fan into the mobo
and that's it! it may look like alot, but it's actually a simple procedure. i would suggest that you buy a grounding strap and some arctic silver 5 thermal compound, however they are not required
good luck