Guys---there is absolutely NO REASON to run the cylinder to TDC before removing/replacing the rocker arms.
The FSM DOES caution to loosen the rocker retaining bolts one turn at a time, alternating back and forth between the pair, so as to prevent distorting the saddle bracket on top of the pair of rockers. Likewise, tightening them is done the same way--1 turn per time, alternating. Final bolt torque is 21 ft-lbs.
I don't own an XJ any longer, but I still think they are the best of all the Jeep products ever made. My XJ was my favorite vehicle in my 50+ years of driving.
So...I stick around and give advice.