Im kind of surprised that there is no one mentioned to take a {censored} punch and marking the shaft and nut with a mark before removing the nut. Remove the nut,yoke,and pop out the seal and replace the seal using a large socket as a driver. Tighten the nut till the marks align and the pre-load is preserved. Insert cotter pin. I didnt use the correct word for the punch having been scolded in the past and censored myself,not wanting to offend the powers to be.I hope nut is still an acceptable word to use.