I have a 94 xj and i have done the rebuild on nss. it is EZ
there is 2 bolts that hold it in and it is pluged in up by the distributer. ounce you get it off it will split like a clam shell with a few screws when you get it apart, brake clean it out really well and dry it back out. take a small peace of fine black sand paper
(Do not wet it) lightly sand the contacts in the nss on each side
then !FILL! it with dialectric grease and put it back together and in
befor you start the jeep slide the shifter back and forth a few times it will be stiff but it is OK the first few times it is used it will be stiff but as the grease gets hot it will breakdown and be better
mine has lasted over a year and i have rebuilt 3 others and no problems.. good luck email is abflexj@aol if you need more help