It's a
really easy DIY project. the hardest part is making sure you don't get the cones too tight or too loose when you reassemble. all you really need is some good bearing grease, a cone wrench and an adjustable wrench, but a vise with soft jaws (wood or copper) to hold the axle while you loosen and tighten the lock nut also helps.
google is your friend:
http://www.google.com/search?client=...UTF-8&oe=UTF-8