pinion seal

How hard is the pinion seal to replace on the rearend

Not hard at all. I've done quite a few of them. After disconnecting the driveshaft, I like to scribe a reference line on the end of the pinion, across the nut, onto the washer onto the yoke. That way you have an idea of where everything was to begin with. Then I use a torque wrench to get a close reading of how tight the nut it currently. Then I take the nut off and change the seal. Pretty easy to pry out and then tap back in. If you have a large socket the same diameter of the seal, it will go easier. Then put it back together with the lines matching up. If the nut it getting tight as you approach lining up with the scibe marks your real good. Just go slightly more and your good to go.

K thanks is there a sealer for the seal

No sealer that I know of. I like to take some rear fluid and wipe the rubber of the seal, in and out, and inside the recess before I install it. Just to lube it a little. Good luck with it.

That's how I usually do but wanted to make sure

You will be OK Only other thing I do is put some sealant on the edge of the metal seal ring, which does make it go in easier and seals the edge diameter.
What Joe73 said is right-on.. Torque it like he said, with reference marks.