First up, your engine needs to be cool, so let it sit overnight before you start working on it. Then, you need the engine to be at top dead center on the compression stroke, meaning the piston is all the way up and both valves are closed. To get there, remove the spark plug so the engine is easier to turn over, then remove the inspection covers from the side of the engine and put a socket on the rotor bolt and turn the motor counterclockwise until the “T” on the rotor lines up with the reference mark on the cover. That “T” stands for Top, as in Top Dead center. If you go past it, just keep going for two more revolutions. Don’t try to turn the engine backwards or you’ll be grinding it against the starter clutch. You’ll notice there’s an “F” on the rotor as well, that’s an ignition timing mark that you can ignore, but it does serve as a head’s up that the T mark is about to appear.