if thats the year range then its probably the dana 44. very simple to tear down and rebuild, and i do mean EXTREMELY SIMPLE AND QUICK compared to the toyota hubs. what hubs do you have the warn premium manual hubs? if so its about 5 steps to tear it down. you will need an SAE allen wrench (cant remember the size), hub socket with torque wrench, flatblade screwdriver, and a phillips screwdriver if i remember right. snap ring pliars as well.
unbolt the 6 screws holding the cap on (allen wrench), pull it off (might need to tap it with a hammer) the spring will come with it. use the snap ring pliers to pull the snap ring off the end of the stub shaft. on the inside edge of the hub roughly 1/4-1/2" into it there is a large ring that you will need to pop out, this is what the flatblade screwdriver is for (this is the most annoying and hardest part of the entire hub). once you get that out, use the hub socket to remove the outer nut, then pull off the washer followed by loosening/removing the inner nut. make sure the brake caliper is off and pull the hub/rotor assembly out. thats it to dissasymble, the outer bearing will fall out from inside the hub and the inner bearing will fall out once you pull the seal off (if the axle shaft didnt pull it off while removing the assembly).
difficult? about as complicated as changing spark plugs. if you have the auto locking hubs its a little bit differant (i've never done it). let me know if you have anymore chevy/gmc questions cause thats what i'm really familiar with (check signature link).
