I had the same thing on my 04 when i changed the plugs last year for what may have been the first time ever (definitely the first time I changed them, not sure about previous owner).
Took me about 8 hours to do all 6. Twist as you pull is the best advice I have. Twist back and forth and pull like hell. They'll break loose.
I tried a boot remover from advance. Nothing. Good old fashioned elbow grease got em finally.
Last time i did them it took 40 minutes for all 6. Maybe 35. Thread grease and dielectric on the boots.
