Remove the brake drums if they're not off already. Put the rear end up on 3 jack stands so it's in the same position it was in the car, nose forward, etc. Put a drain pan under the center & remove the cover. Sometimes the bottom bolt hole will connect to the inside, and the oil will come out the hole. If not, loosen all the bolts 2 or 3 turns, then pry the bottom of the cover outwards to let the oil out.
Turn the differential carrier until you can see one end of the pinion shaft and the small bolt head a little to the right of the shaft. That bolt retains the shaft. Remove the bolt, then slide the shaft out toward you. You may have to stick your finger around to the other side & give it a shove. This picture shows the retaining bolt partially unscrewed.
Once the shaft is out, don't turn the driveshaft yoke or axles any more than you have to, because if you do, the pinion gears (spider gears) might move out of place & that can be a PITA to get back right. You'll need to turn the carrier back a bit to get access to the inner axle ends, but only a little bit.
Push one axle inwards about 1/4" to expose the C-clip on its inner end. This can only be done after the pinion shaft is out. Slide out the C-clip (a magnet-on-a-stick tool is good for this), and then do the other axle. Slide the axles out.
Inspect the axles where the outer axle bearings ride. If there's a groove about a half-inch wide, the axle should be replaced, along with the bearing. If you can see a pattern but there's no groove, you're OK. MIght consider replacing the bearings anyway while you're this far in, but it's up to you.
Remove the axle seals. There's a tool for this, but a good-quality claw hammer usually works for me. There's also a tool to install the seals, but the same hammer & a chunk of 2x4 work fine if you're careful not to distort the seal. Install the seals (with a touch of oil on the lips), axles, C-clips (push the axles outward so they don't fall off), pinion shaft, retainer bolt, & cover. If the rear's out, you can drop the nose down and pour the oil in before installing the cover.
DO NOT TRACK THE NASTY STINKY GEAR LUBE INTO THE HOUSE OR YOU WILL BE KILLED.