It should be on the side of the engine, and it may be under a rubber cover. Remove the cover if present. You should see the cap with 5 wires coming out of it. (Spark plug wires). 4 plug wires and a coil wire. The one in the center is the coil wire. Draw a picture or something to remember where each plug wire goes on the cap. This is important. Then unplug all of them. There should be 2 screws holding the cap on. Remove them and take the cap off. Then you'll see the rotor. Pull it straight up. It may be kind of hard so pull hard. Then put the new one on. Put the new cap on and screw it down. Plug the wires back where they were on the old cap and fire it up.