I am going to assume it hasn't changed since inception. Is the bottom of the shaft (that came out) splined? Does it twist normally to shift before the problem?
If yes on both questions the spline inserts into the shifter cam female spline directly below the hole where the shaft inserts. The shifter cam is preloaded from the cam follower on the front of the prop shaft. With the preload, the cam is pushed away from the optimum position for stabbing. Trying to get it back together from the top is a trick for the best of magicians.
Probably you will have to pull the prop shaft and F gear and shims if any, to get to it. With the prop shaft pulled the preload is removed and the cam can be positioned manually to line up with the hole and shaft spline. Pulling the shaft requires pulling the bearing carrier assembly at the rear of the LU through which the shaft protrudes, R gear and any spacers, and the prop shaft with the clutch dog and cam follower attached. The bearing carrier is held in place with a large spanner nut, visible once the prop is removed. It mates to threads cut into the inside of the circumference of the rear of the LU (about 4 " in diameter}. Good luck on getting that nut off on your year model. Corrosion will have done it's dirty work. You will have to cut it out...Dremel grinder is an option. I have explained the operation of this shifter previously and would be in the archives.
