I ran Techron through my fuel system for several tanks of gas getting ready to do the plugs. Cracked plugs a 1/4 turn and used PB blaster on a warm engine, let soak 10 minutes or so. Then used a 3/8 electric impact gun on all but the two rear plugs (no room for my impact). On those I just took my time loosening the plug a little at a time until it felt tight or "funny" at all. Then I would jump to another plug and work on that and come back to the rear plug after the PB soaked in more. All 8 of my original plugs came out in one piece from my 2004 with 96K miles on it.
I ran 2 tanks w/ techron, warmed engine , 1/4 turn plugs loose drivers side. sprayed w/ pblaster, whole side came out in 1 piece. rewarmed engine, did the same for the other side, none broke. Engine had 105k on it, at the time. I have found magnetic plug socket works best for me, in this application.
I've changed the plugs in my '07 F150 5.4 3V twice, 95,000 miles and 191,000 miles. Both times in the three fill-ups before the plug change I added a can of Seafoam, then with a cold engine I cracked the plugs about an 1/8 turn and poured Kroil into the spark plug well. Waited two hours and then, carefully, removed the plugs. If any showed resistance, I would screw it back in then screw it in and out, each time screw it out a little further until it eased up. Once they were all out, I reinstalled the PCM to spin the engine over to clear out the Kroil that dropped into the cylinder.
I used nickle based Never-seize on the new plugs.
So far, sixteen plugs and none have broken.