Haha...replacing the glow plugs is the easy part...but first getting access to them and then later bolting all those parts back is a little more complicated.
In short, getting clearance to place a 10mm socket on ALL of the glow plugs involves removing the battery, the alternator, which means at least first loosening the serpentine belt tensioner, and then also removing the intake elbow, which means disconnecting the intake elbow from the intake, the dipstick, a hard line clamp and ALSO the EGR valve exhaust pipe... THAT part is NOT so easy...patience, good lighting, good eyesight, good tools INCLUDING several long, 1/4" drive ratchet extensions with a decent wobble tip are key here!!! Removing the intake elbow involves working both beneath and on top of the engine.
Even then, after hopefully easily replacing the glow plugs (PB Blaster and compressed air are your friends here... both to loosen up the glow plugs and to keep ANY debris from falling into cylinders), you STILL need to put it all back together again!!! And, I gotta say that, at least for me, reconnecting the intake elbow to the EGR valve exhaust pipe while still keeping the elbow aligned to the intake was the most intricate and difficult part of this job!!!
Oh yeah, if any or all of the glow plugs seem difficult to turn counterclockwise while removing them, be SURE to patiently and slowly work them BOTH in and out of the cylinder head...alternately loosen them a little and then tighten just a little, in order to clear the threads...in other words, do NOT use too much force by simply trying to back them out or you might come to regret that. A little PB Blaster can help here too , but be sure to clear any debris with compressed air before finally removing the glow plug.
All that said, do NOT let my words discourage you..its fun when it’s done!!!
Of course it also goes without saying that it helps ALOT to have an assistant who can at least hand you the correct tools and help focus a good work light as you are laying under the Jeep.