6 cyl Rear main seal

[Tufftruck]

Hello:
I have a 71 D-100 with a 225 6 cyl and I have the front axle and leaf springs out because I am replaceing the bushings, king pins, brakes, seals, you know all that stuff for the front end. Well while I have all that out there is nothing in the way of the oil pan. So I am thinking about replaceing the oil pan gasket and the rear main seal. My question is, any thing special I need to know before I pull the pan and the rear bearing cap to replace the seal? Any info will be helpful.