You may have to take drastic measures to get it off. Blue wrench (aka TORCH!!). Hack saw?? If you have to do this, you will need a new steering box. Make sure you look behind the dash BEFORE you do anything drastic. You want to find a shop/store that sells a replacement for what ever is back there before you wreck anything. Boat US, West Marine, and the other big names in marine "stuff" would be a good place to start.