[Wonderinlost]

Dremel tool, cut a grove in it and pop it with a small hammer and chisel. Butane torch would do the trick also but might catch your boat on fire when the rubber takes off, so ignore the last idea. Defiantly put antisieze on it when you go back with the new one.

I agree if you can cut a grove in it to the shaft. Just like removing stubborn berring races on a trailer.