Hi Mike,
Its a pretty straight forward exercise, as stated by the other raiders.
Mount the pump at the lowest point.
Run the hose with the minimum bends and length to either a skin fitting through the side or over the gunwhale.
Depending on whether the unit has an integrated float as to what the wiring will be like, or if its just a manual setup.
I don't know if your tinny has a floor or not? but having an automatic setup will mean pump will be on before your ankles start getting wet.
Most pumps from my experience if of US origins are rated in US Gallon not imperial which is 3.8litres not 4.5litres.
I am down the coast this week but will be back sunday, if you would like, I could come and have a look and give you my ideas, as you are in Leichhardt also. I'm in Catherine Street.