Razor blades rule.
I used a razor blade in a holder to get mine off. It was last winter and cold, and I think that helped. As i was slowly easing it off, I stumbled slightly and heard "zzzippp" from the blade. I thought i had gouged the gel coat, but NO, the noise was a couple of feet of tape that had come free. Hmmm, I thought, let's try that on purpose this time! So i took a rush at it and off came another three feet. The whole thing was done in four minutes flat. As stephen said, a little acetone on a rag cleans up the residue. I haven't tried the WD40, sounds good though, as long as it doesn't make the adhesive gooey, which would spoil the zip effect!Good luck.