Installing new parts.
First: Materials used (New pinion/oil and grease seal, PVC coupler for easy mounting)
*This step is much easier if you can find something that perfect fits the edges of the seal so you push it into place(PVC Pipe or the top of an air tank). I don't recommend using a hammer, as the outter part of the seal is pretty fragile. I used the top off my acetylene tank to do this, fits perfect.
Place the seal into the differential and place your coupler or any device with the same circumference as the edge of the seal and slightly hit it with a hammer to wedge it in for a good tight seal. The seal itself has a spring that goes around the yoke and holds after fully secured. Once that is done, use sand paper to touch up the edges on the dust cover as to not let anything harm the new seal. Once it has a clean finish re-install it on the mounting plate.
Second: Materials used (1-1/8" Socket and Impact gun)
With the seal and dust cover in place, reinstall the mounting plate for the drive line.
The plate will go into the groove of the seal once enough pressure is placed on it. This plate has teeth on the inside of it, so make sure you align it with the yoke properly. Use a hammer to make sure you get the teeth biting in the proper place. Don't torque it down until everything is aligned.
Now with the plate on, use the air gun to tighten the nut and force the plate into the seal. Once all the way in, use a torque wrench and set it from 120-140 ft lbs. (Check your manual)
Third: Materials used (12mm tweleve point wrench and a buddy)
With the mounting plate back on and the seal finished its time to bolt up the drive line. So loosen the ratchet strap and place the drive line up on the mounting plate. If may not align perfectly, DONT PANIC! Get a friend to take the truck out of 4WD, with the e-brake and blocks still set. This will give the drive line a little play so you can line the 4- 12mm bolts up perfectly.
Then use your 12point 12mm wrench to torque down the bolts and fasten the drive line securely.
Finally: Materials Used (SAE 80W-90 gear lubricant)
Re-check that everything is torqued to the proper specs and put some gear lubricant into the diff's. Un-block the tires, and go for a slow test drive to make sure everything is in proper working order.