Randy's ring and pinion book is a good book for somewhat of an experenced mechanic.
To answer your question you could pull the axles, remove differential, slide spider gears out and replace with new ones. I also would suggest taking the truck somewhere to have it done right R&R all the bearings, cleaning out axle, setting gears up, etc. But if you don't have the money in these times, with careful inspection of the other rearend parts, and cleaning. I see no reason why it can't be done. I have seen the limited slip rearends chew the spider gears up when one wheel is spinning to fast for the limited slip to engauge, or when it does engauge it tears spider gears, positraction unit etc. I am quessing that you have a limited slip since you have a Z71. I couldn't tell you if this was the cause so you would be spending time and money on the wrong problem possibly. Your better off trouble shooting and repairing the problem that caused the spider gears to tear up or have someone with the tools and experience to do it. Also Installing new spider gears would not require the rearend to be set up.