I want to remove centerboard from my 5.2 to change up/downhauls and refinish. I unscrewed the 4 screws from the pivot casing, and tried to pull centreboard down without sucess. Pivot casing seems to have been glued or sealed in at some point. I tried to scrape around casing and force it off, but I didn't want to apply too much pressure in case it broke. Any suggestions?