Remove cap from boat's deck waste fitting
Insert hose nozzle into deck fitting. (You may need an adapter to make it fit. Marinas generally have them available. They are also for sale in boat stores.)
Turn pump on. If there is a hose valve, open it to start suction.
When waste is no longer seen in sightglass, close hose valve, turn off pump and remove nozzle from deck fitting.
If a water hose is available, rinse the boat's tank and pump dry.
Put the pump nozzle (with open valve) in a water source and pump water for 15 seconds to rinse the hose.
Close the hose valve. Put away hose. Turn off the pump and replace the deck fitting cap.