If you were lucky, a tool kit should be with your moped. If you have a 50v it will be behind the chrome side plates under the seat. It will look like a thin socket and a handle will fit over to turn it. Wow, its a hard thing to explain but look on your moped for the kit and youll figgure it out if you find one.
If all else fails, find a socket set. Almost all socket sets have a socket to take off spark plugs. It will be the real long, deep one.