After this thread, I changed the original spark plugs in my 2015 Expedition Limited 4x4, purchased new. I did the work with the engine cold. The coils were extremely difficult to remove. I used a thick plastic trim pry tool to remove several of the coils. Some of the coils could be rotated slightly, which helped. I felt as though some of the coils were sticking at the top seal, not the boot around the spark plugs. I used a small plastic trim tool to slide under the top of the coil seal, and break its contact with the metal plug tubes. I eventually got all the coils off and replaced the spark plugs. I used a liberal amount of silicone dielectric grease on the top portion of the coils before I reinstalled them, especially around the collar seal - to help in future replacement. Ford designed the coils very poorly and made an easy maintenance job very difficult. I would guess it took me about two hours of time. If the dealer is charging three hours of labor - they know how difficult it is, but that still seems very excessive for a trained mechanic. I wonder what the actual “book time” is? I do not tow, and use top tier fuel. At 45,xxx miles - the spark plugs were black and burned, with the electrode gap opened. The plugs looked like they had 200,000 miles on them.