I finally got around to removing the antenna due to being busy flying or other non-flying activities.
Thanks Jim, I had forgotten about using a hair dryer. It worked like a charm, had it off in less than a minute.
While heating it up, it twisted cleanly off from the antenna. I was then able to 'roll' the adhesive off the plane, only left a few small pieces which came off with Goo Remover. Took a little longer time to remove with Goo Remover.