Just did the rear pinion seal on my truck tonight and even though I forgot to take pictures, I figure I could do a write up to help some people out.
First off, mark everything with a paint marker or Sharpie. The rear part of the driveshaft has to come out so mark all the mating points so it goes back together how it came apart. Also, mark the pinion, pinion nut and yoke on the differential so these line up correctly too. Everything needs to go back how it came apart so it is in balance.
After that, remove the driveshaft by unbolting the two u-joint retaining caps at each end. They are 8 mm. I replaced the u-joints while doing this since it was already out and didn't take much longer to do.
After that is out of the way, spray a liberal amount of PB Blaster on the pinion nut. Let it sit and then take the nut off while holding the yoke in place. I used a 1 1/8"(I think) socket and a pipe wrench. Once off, use a 2-jaw gear puller to remove the yoke.
When the yoke is removed, some fluid will drip out. Be sure to have a suitable container under it to catch the fluid. With the yoke out of the way, take your favorite screw driver or seal puller to remove the old seal. Once done, put the new seal in by tapping carefully around the edge of it until it is completely seated.
Once that is in, everything is just reversed. Make sure everything is good and tight. I put anti-seize on the pinion nut and lock tite on the u-joint bolts. Torque all bolts down to factory specs and check the fluid level in the differential. I decided to drain mine and fill with Mobil 1 to have some peace of mind.
Obviously this is meant to be a guide and I take no responsibility for what you do to your vehicle. Take all safety precautions before, during and after working on your vehicle.