"Sorry if this sounds like a dumb question, but how bad of a job is it to change the plugs? I've held off because of a fear of snapping them off, but it is time that I take care of them (possibly the factory plugs, 145K)."
A few tricks make this an easy job:
A quality "wobble" sparkplug socket. not the u-joint type. A quality socket it less likely to crack an insulator during installation. A 3" or 6" extension will help on some, but others are best with just the socket on the ratchet.
An old plug boot off a discarded plug wire as an installation tool to hand start the new plugs. Better and safer then using the socket to get it started.
If you have a compressor and air ratchet, makes for quick removal, but I prefer to hand tighten once threaded in with the boot. You can also blow out around the old plugs prior to removal.
Plug wire pliers are great, especially if you are reusing the existing wires. But the trick to getting old wires off the plugs, twist the boot until you hear or feel it break its grip on the insulator.
I like a dab of anti-seize on the plug threads.
Always check the plug gap. Never assume its right out of the box.
A little silicone paste/dielectric grease on the boots prior to plugging them on the plugs.
