Its pretty easy to adjust.
Inside the jeep remove the shifter boot.
Put the transfer case in 4L.
Put a 1/8 in. spacer between forward edge of the shift lever and the shift lever gate.
Outside....Jack up the jeep and loosen the lock bolt (2) on the adjusting trunnion (3) then move the range lever fully rearward to the 4L position (5)
Set the linkage rod (4) so that it sets freely in the in the range lever (5) and tighten the adjusting trunnion bolt.
Lower the jeep and remove spacer from the shift lever and try it out.
Make sure you support the Jeep before you climb under it.