If I were doing it in the car I would take the pinion housing bearing assembly out and do it on a bench. Undo the bolts just behind the yoke and pull the assembly out. There are shims between the housing and the case. Make sure and don't lose them. They set the pinion depth. The
oil seal is a big O-Ring around the bearing housing. You will see it when the housing comes out. When you put it back in put some lube on the O-Ring so you don't cut it. You can put the yoke in a big vise or holding fixture to undo the nut. It is easy to set the pre-load with it out to.
Wayne
