There are a few things you need to know before starting this process. The first is that the engine must be in a good condition, as it will need to be rebuilt if it is not. Second, the boat must have a place to put the engine, and this can be done by either buying or renting an engine bay. The third thing you will need is some tools. These include a jigsaw, saw, drill, and screwdriver. Once all of these things are in place, you can begin by removing the old engine from the boat. This can be done by using a plunger to push and pull on the engine until it comes out. Once it has been removed, you will need to clean and dry the engine before putting it back into the boat.