Not to replace the seal. If I recall correctly you just pull the axle out, replace the seal and put it back in. You only need to cut the collar to replace the wheel bearing.

Since I didn't want to replace the bearings, I used to just pack low-temp wheel bearing grease in the old bearing and on the seal which quiets it down and stops the leak for another year ...

The 1975-up axles have two seals; I've never worked on one of those.