If your doing this yourself I would take pics. Since my eyesight is not too good when I did mine I took pictures with my Hy res camera and save them to a Hard drive. I took pics of the bearings and seal. So the next time I can get them ahead of time.
2001 Ford F-350 DRW 7.3
2011 25 RL Wildcat
former fiver 1976 Fourwinds had for 35 years