Denso 671 6241 Coil Over Plug Review

So the plastic/rubber used may not be suitable for the temperature. Or the terminal at the end of the spark plug must be too good. I had a misfire problem on cylinders 4, 5 and 6 (not associated with this) and I went to remove the coil packs and they wouldn't come loose, kept pulling, eventually it came loose from the top of the trunk. For the sake of my life if I can't get the boot out to get the spark plugs out without wrecking these boots. Which were expensive enough not to want to tear them