I had that problem on my #6 cylinder. #5 came out with crazy glue. Should mention that the previous owner changed 1-4 and left 5 and 6 alone. Able to tell because those two had blue NGK writing, the others had green. I used the $6 per tube caulk at the local home despot. Let it sit overnight with the coil pack screwed in. Next morning, I unscrewed the coil pack and pulled up. The boot came out! Needless to say, I replaced that wire. Going to replace the others soon. No codes there but they do say Nissan and I imagine they have 204 k on them. Hope this helps someone

 

Make a hook with some wire that wont bend when you push on it ...and fish away

 

tried that, coat hanger didn't work, neither did the tools with hooks a mechanic tried, yeah I know, but it was driving me nuts. Also tried a brake spring removal tool, not quite long enough. you can get 11 inch needle nose from the former online book dealer named after a river in South America.

 

Get a real long skinny screw driver and stab it through the boot. Then slowly maneuver it out. That was my last resort after hours of frustration. I was to the point of breaking stuff intentionally lol. It worked for me.

 

The caulk was painless, I can get way to creative with methods of destruction sometimes and since I don't have the title for my car yet..

 

I got the boots out of 5 and 6 with a metal hook with a sharp end to it. Keep trying just make sure you don't tear it up either