Once it's off, watch out for the glass itself, mine came apart easily. It had glue holding it in, I could see where a large drop had been applied to hold it in the ring, but the whole drop had broken free and the glass came loose. The filter is larger than the lens and covers so much extra that the glue drop was out of frame.
I wasn't worried about it at first because I planned to keep one of the Polar Pro filters installed all the time, even it was just the polarizer. But I found I need the stock filter when I'm shooting panoramas. The polarizer works like it is supposed to, which means SOME parts of the blue sky get darkened more than others, making it harder to blend with the other photos. So I'll be gluing the glass back in the stock filter soon.