[Ford Man]

Twisting and pulling on the boots at the same time will usually break them loose. If the boots are easy to get to you can wrap a rag around the boot to keep from damaging it and use a pair of pliers for more leverage if needed. Be sure when you replace the plugs to use anti seize on the threads and dielectric grease inside the rubber boots on the plug wires so they won't be such a pain the next time.