"Because of water leaks(oil leaking from the gear case)I tried to change the seals but after removing the water pump base I couldn't remove the bearing assembly and .... My engine is 74' merc 500 4cyl 50HP. To remove a drive shaft and a prop shaft,Do I need a special tools? Should I disassemble drive shaft first or prop shaft first? I have a factory manual and diagrams but It doesn't help. Someone can help me? noah"