You add a bilge (not bilage) pump by creating a "lowest" spot in the boat. ( Think sump pump pit for a house.) If you have to cut a hole, it must be just ahead of the transom because that's the lowest spot and where water will collect. You cut the hole in the center, and big enough to fit the pump and attach the outlet hose. Of course you need to make sure there isn't a center transom support or other structure in that area. Route the outlet hose to a fitting installed as high on the side of the boat as possible and via the shortest route.