Or save yourself $50 and get the kit from Cummins... which is in the guys "kit". The stock seal is single lip, the one that comes in the Cummins kit is dual lip.
He has some seal drivers, which sockets or pipe work just fine for, and a DVD... well the instructions in the Cummins kit are very clear on how to do it.
I tore mine apart not knowing anything about it and I had it all done in a Saturday afternoon, with the worst part being removal and replacement back in the truck. I also found the brace that goes to the steering pump was about to fall off, as well as a few of the nuts holding the pump on, so it was a good thing I fixed the leak!