I replaced the plugs on our yukon with the same 6.0 motor as yours last year. It is a fairly easy job on these. I do not recall having to remove the coils to do it. I used new acdelco wires and Bosch platinum +4 plugs. The hardest part was the passenger side, the one near the firewall and the one near the alternator if i recall correctly. I used a flex head ratchet, a universal joint, and maybe a few different extensions. I put dielectric grease on the porcelain so hopefully the new boots will come off easily next time, and antisieze on the threads. Remember to put the heat shields onto the new wires. Your cylinder heads are aluminum, so be careful getting the plugs out and in as the threads are easily damaged. Only change plugs on aluminum heads with a stone cold engine. If the plug is stuck because it has been in there so long,You can try tightening the plug very slightly to break up any carbon that has siezed it before backing it out a little, tightening a little, backing out a little more, until it comes out.
