New Diff

Remove 4 nuts from the 4 studs in the hub that hold the axle shaft to the housing. Disconnect the e-brake cable and brake hard line from the drum (do each side), then slide the axles out. They usually come right out with a slight tug, but if they are in tight, a slide hammer or the like may be needed to pop them loose. You can either just slip them out a few inches, or remove them fully. Just watch that you don't mess up the inner oil seal inside the end of the axle housing.

Forgot to mention if you have rear ABS, I think there may be some precautions to take with that. I've never dealt with it, but would be worth checking out before proceeding. The Factory Service Manual would have the details:

And there are a couple of good writeups on rear axle maintenance on the page below:

no abs. i'm getting powertrax no-slip diff. the oem diff slips way to much (and it's a 4x4)....

awesome info, thanks.