Just changed the plugs on my Hemi and thought some might find a write-up useful?
First thing is the tools (see first picture)
1) 3/8" drive (could be 1/4" or 1/2" with the right adapter)
2) Spark plug socket
3) 10mm socket
4) 10mm wrench
5) 2 3" extensions
6) 1 6" extension
7) Spark plug gap
8) Angle adapter
9) Compressed air
10) Torque wrench
11) Dielectric grease
Note the second picture where it shows the connector disconnected from the ignition coil. My setup is different from that found on wkjeeps.com. I have 8 'banks' of 2 plugs. In each bank one plug is underneath the coil and the other is right next to it with a normal plug boot. wkjeeps.com shows both plugs under the coil.
The first thing to do is notice that there's a small tab, pointed to in green, that needs to be pushed up towards the center of the engine. You really can't see it too well but it's in the green part of that connector. As this is pushed up you can use a flat head screwdriver to pull back the tab pointed to in red. After this push down on the connector with your thumb, pointed to in blue, and pull the connector towards the center of the engine.
After this remove the two screws pointed to by the yellow arrows. These are 10mm and are self retaining so you don't need to worry about backing them out all the way and dropping them somewhere where they don't belong.
Next just pull the coil out to expose the plug. Now you'll be able to get the plug socket into the hole so you can remove it. Before you do this and remove the plug blow some compressed air into the hole. On many of these you will be able to look and see if there's any junk in the hole. After blowing some air down there you can remove the plug. See the third and fourth pic.
Now you can remove the plug wire just to the back of that front plug hole. This boot comes out by simply pulling and twisting. Don't pull on the wire itself but rather the point at which it enters the hole. Now you'll be able to blow air in this hole and remove this plug. You should actually remove this boot before removing either of the two plugs. You don't want to remove the first plug and then remove this boot and have some junk fall back into the first hole and then into the head.
Now that you have the plugs removed from a bank take 2 new spark plugs (Champion 570 or equivalent) and gap them to 0.045. I've heard nothing but bad things about anything OTHER than copper plugs!!!! Research it yourself if you don't believe me. Anyway, I decided to put some anti-seize on the threads of the plug. Nothing excessive, just lightly fill the threads of the thread shank. After this I put a bit of dielectric grease on the ceramic part of the plug.
Now install the plugs and torque them to 12 in-lbs. Thread the plugs as far as you can with your fingers as you don't want to go crazy with the wrench and cross-thread them. You should be able to thread them by hand almost all the way. I really only needed to do at most a 1/4 turn with the wrench. Now just reinstall the plug wire/boot and the ignition coil the reverse way that you removed them. I put a bit more dielectric grease on the inside of the boots before reinstalling them.
Repeat for the other 7 banks (pairs). I found that the hardest bank to work with was the front drivers side. This is where the 10mm box wrench and the angle adapter came into play. The rest were easily accessible with various combinations of the 2 3" extensions and the 1 6" extension.
Hope this is useful to someone. Good luck!
Forgot to mention to remove the oil fill cap, remove the shroud, and put the oil fill cap back on first.
Last comment, if you're like me you'll start the motor and run it for a minute or two after doing each bank. If you get a OBD engine light you probably forgot to put the connector back on.
( I know from experience ) Don't panic, just put it back on, with the motor OFF, and recycle the motor a few times. That or you can just remove the negative terminal of the battery and reset it.