I watched a mechanic once take out old difficult plugs on a v8. It was a rather slow process where he alternately turned the plug out slowly a turn or so, then sprayed lubricant into the plug hole. Then he'd tighten the plug back into the hole a little, repeating this process until the old spark plug came out with the threads undamaged. The lubricant that you choose will not damage anything and will be beneficial for installing the new plugs. Torque them to approx. 15lbs.
+2 on this method. I prefer PB Blaster myself...
Have removed many a stuck rusty bolt/nut with the same method (inclucing the little 10mm nuts that hold the fuel pump in place on a Legacy...). Time consuming, but if it works without breaking things, you take the time.
Yeah I already got the plugs from another older list on that topic.
I just wondered if anyone had ever sprayed into the plug areas...
I'm not even going to pull off the wires if I do it, I'm afraid they'll
break too if I try to remove them.
If you are so afraid of the wires, then perhaps they should also be changed? Old, brittle wires are not a good thing.
OEM or quality NGK wires - pull one at a time, match length and install - no problems, good to go.