I pump almost all the gas out (I use only non ethanol gas) and pour into the car/truck. Run the engine dry on what gas is left, then change the oil. Remove spark plug, put a very small amount of oil in the cylinder, and crank over a few times to spread it out. Put in new spark plug. Clean/Replace air filter. I do my neighbor's standby gen, and change her oil filter also. I keep a gas can with non ethanol gas (with stabilizer) around for emergency use, and dump it into the car/truck in the spring if not used.
Doug