Rear Tranny seal install

I am pretty sure you can just pry it out carefully with the tranny installed, and the drive shaft out. I would definately use a genuine FoMoCo part. Then tap the new seal in using a socket of the exact same diameter of the seal or a piece of wood cut to that diameter so it goes in evenly and doesn't warp. They may even make a tool specifically for this. Do it slowly, watching to make sure it is going in evenly. I have never actually done this, so I would refer to a manual to see if you need to use some sort of lubrication, or maybe someone smarter than me will chime in on this.

Apply with your finger a little ultrablack on the inside where the new seal is going to mate up to the tailshaft housing and you should be good. That will lube it and when it sets it's sealed for sure. I just used a hammer and lightly tapped around the seal. Dont forget to grease the seal when you install the tailshaft.
Kevin