Yeah, they don't quite have it right.
First, remove the transfer case shift bezel.
Second, you need to pull the transfer case shift lever into 4LO, then place a 3mm (1/8" in) shim between the lever and the shift gate. Anchor the shift lever in that position, pressing against the shim and shift gate, with a bungee cord.
Third, crawl under the XJ and locate the adjusting trunnion block with the locking bolt in it--up high. Loosen the locking bolt.
Fourth, manually shift the transfer case into 4LO fully. You can do this with a prybar or large pliers working against the transfer case shift tab--where the lower end of the low shift rod attaches.
Fifth, tighten down the trunnion locking bolt.
Sixth, remove the bungee cord and shim, replace the bezel, test the transfer case.