if you need a wiring diagram just to find the starter then you dont need to be working on it.
i take it your new to this so i will make it easy. start at the battery. follow the cables. The positive goes straight to the starter. If it doesn't have cables then look underneath where the engine and the transmission bolt together. It will be right there. If there is no starter then look for the big hole with a couple bolt holes around it. Inside there will be a big circle thing with teeth on the edge. Its called a flywheel. It goes right there.