I just purchased a 2008 Nitro 898, I'm in the process of putting it away for the winter. The back pedistal seat is on a Swivl-Eze Lock'N-Pin, a 3/4" Pin Seat Mount with a spring on the shaft, the seat is about 4" up off the deck. I've never had this type of mount before, how do you detatch it from the deck?