>Pry the seal out with a large screwdriver or bar (you might have to destroy it with a chisel from the side). Put some grease around it for easy replacement with a hammer if needed.
>Put the yoke back in in any position.
>Put a large pipe wrench on the yoke, get out your 1/2" drive ratchet and breaker bar, tighten the nut until the yoke is a little hard to turn when wiggling it back and forth.
>You are done unless the nut won't get tight which is very important.

The only purpose of the crush sleeve is to keep the nut tight. It has a ridge on it that bulges out to maintain pressure on the nut but allow the bearings to tighten also. Type "crush sleeve image" in Google if you have never seen one. You can only apply so much torque after the sleeve starts crushing so a torque wrench won't help. Normally you will have a renewed shot at more "crush" on a used rear end pinion because the bearings wear increasing the distance between front and rear pinion gear bearings (but the sleeve stays the same length). If the nut won't get tight without imposing too much drag on the pinion (very hard to wiggle back and forth) there are ways to fix it.
>You can go get a new crush sleeve (it should slide out after you slide the front pinion bearing out)
>You can put the sleeve on a pipe or something and flatten out the ridge a bit.
>You can install a thin washer or shim in front of the sleeve.

If the nut gets tight about the same time the pinion achieves a little drag (a little harder to wiggle back and forth) but not quite tight enough you can back it out and apply some seizing compound on the threads, and re-tighten until there is a little drag on the turning of the yoke. You can also stake the nut with a punch.

PINION BEARING DRAG; Don't get too hung up on this because I have seen used rear end pinion bearing drag that ranges from none to very tight and they all work fine, in fact they all loose their drag eventually anyway as the bearings wear. The reason for the drag (which should amount to about the pressure to turn a viscous drive clutch fan flange) is to assure you that the the bearings are snug so they will maintain good clearances at the ring and pinion. If you prefer to get a new sleeve get a new nut at the same time.