This is NOT your motor. Postiing it for reference only. If your motor does not have the clip mentioned above, then the forward gearcase stud goes way up to below the steering pivot king pin and is held by a special nut, which requires removing the powerhead, then pulling the king pin out. Now you can access that special nut, which requires a special screwdriver.
Note: if you have this kind and the sliding vane pump, I suggest leaving it alone till you get it running. If it pumps water at idle speed, the vane is ok. If it doesn’t pump, or doesn’t pump at idle, the pump requires attention. The ends would wear on the sliding vane, and the first indication is no pumping at idle.