I've found this video that's pretty cool for explaining how diffs get set up, what preload is, the difference between crush sleeves and preload shims, how to mark the teeth on the ring and sight for alignment under load. It's pretty useful.
Basically, you can get a good idea how to work on your own rigs by subbing in numbers from your FSM over what he says in the video.


Edit:
It looks like the vice he mounted the diff into is one of these:

A Bench-mounted holding fixture.

 

http://www.gearinstalls.com/ additional info

 

Thanks Dropzone!

 

Years ago, with my limited abilities, I removed the 3rd members and pinions from a '74 CJ (pictured in avatar) and my still very driveable '89 Toy p.u. to replace the bearings and races. I didn't/don't have the talent or finesse that I saw in the 'gearinstalls' site...just went by shade tree feel and after 100k+ miles since the bearing/race swap there's probably going to be a 3rd member failure in the future.

I thought I knew what a ring and 'pinion' gear were but was stumped when I read on a recent post mentioning a 3rd member set up w/ 2 pinions and /or 4 pinions. I 'searched' here and googled with no success and my mind can't picture a ring gear w/ more than one pinion. It would be much appreciated if someone could enlighten me. Please do not type to quickly, I'm slow witted.:

 

The 2 or 4 pinions referred to are the small gears inside the differential carrier housing that connect to the differential side gears that the axles splined ends socket into.
A 4 pinion setup gives double the tooth contact between the axle side gears, so more strain can be handled without failure

 

Just finished the 'dif' video above. I feel pretty lucky that my truck is operable. I,m sure the wear pattern on the ring gear would be way off. Some day I might take a peek at what my gear looks like, just hope it isn't because of necessity.