Thanks for all the inputs. I used a 1/2 inch breaker bar and the 2 foot pipe that came with the boat for zinc removal. The plug did not move but, the square end that fits into the socket broke off. It was a 3/8 inch socket. I never had to use this before to remove the zinc. A mechanic friend is coming over next week and we will work on it. When I removed the rear zinc, I noticed a lot of white crud inside the engine and on the old zinc. I think that the engine needs to be descaled. There is always more work to do.
