If you want to do it yourself here is the tool that I use.
http://buy1.snapon.com/catalog...talog
Snap-On valve spring compressor...
All you have to do is put a folded rag underneath the valve your working on, compress the spring, then pick out the pair of collets with a little magnet. Then you can remove the retainer, spring and valve
Installation is easy also. Just place the collets in the retainer and place on top of the spring. Compress down the spring while using a finger to hold pressure down on the collets. If the Spring is compressed down correctly the collets will seat themselves between the retainer and spring. This will probably take you a few trys but you'll get it.
-Bluefire