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Im afraid to say the only way to remove the plugs from the head is to have the truck towed to the dealer. This is a very common problem with the 4.6 and 5.4L engines. Ford has a special tool to remove the rest of the spark plug that is in the head. This is the safest way to go without damaging anything else in the engine.
Ohh ok, That is fine. Whatever is best for you