I'm not up there, but from what I understand you have to pull the head to get the lifters out, pull your radiator and condensor(if you have one), to slide the cam out, loosen oilpan to pull timing cover. I would say that if you are gonna go through all that, just pull the engine out, put it on a stand clean it thoroughly before disassembly and then do it. You might as well buy a complete gasket kit as well since you gotta pull the head and oilpan. Replace your front and rear seals, and check your rod and main bearings.
Of course you could do it in the jeep, but way harder. If it's gonna be down, migh as well do it right.