Just bought a 72 Glastron CV-16SS. Has a 4 cyl. Volvo Penta B-20 1000006. My question is I'm trying to take prop off. But it has this what I will call a nose cone that has a hole in it that goes straight thru close to tip of cone. Then goes down to the inside of prop and has 3 slots in the prop where this nose cone base can be seen. How do I get that darn thing off before taking prop off. Any help would be great. Thanks in advance.