Re: green 47
The water pump is right above the flat anti-cavitation plate. That is about as much as I can tell you without knowing more about your motor. It may have a rubber impeller and it may have a sliding vane type. Methinks sliding vane. If so, you have to remove the powerhead and pull the steering swivel pin out to access the nut holding the front stud that holds the gearcase on.
Brian Wilcox makes the rubber impellers. You are on your own if it is a sliding vane. I made mine out of Delrin. That takes a bit of patience.