I replaced my hub bearing today on my `04 Silverado. The old bearing had 125,000+ miles on it. The job was not so bad.
The hardest part was getting the old one out. I sprayed lots of PB Blaster around it, and beat on it with a hammer. After a few minutes it popped right out. There was a lot of rust in the knuckle bore. Cleaned it out with emory paper and a wire wheel brush on a drill and then lightly greased the bore and surfaces.
The truck rides and steers a lot better now.