You can just run the fuel out and it will be fine, if you want to do more:
Pull the fuel line off and start the engine. After a few seconds spray wd40 in the gas inlet of the carb then let it run out of gas as you choke it to keep the rpms down.
Then take the spark plug out and pour in 1/2 a cap full of ATF, Marvel Mystery oil or just motor oil with the exhaust port closed, give it a minute to run out to the cylinder walls then turn it over a few times by hand. Don’t use too much oil.
FAA certified jet engine and aircraft technician,
Nicholson Speedway class champion 2001,
Yamaha KT100 Service Center,
41 years karting experience