How do you drain bad gas out of your lawnmower?

it depends... if you have a drive mower than you should have a hose that runs from your gas tank into a fuel filterer you unclip it the gas will leak out you can probly find it if you locate the gas tank just look for a tube,and if its a push lawnmower you should do the same,or you can tip the lawnmower over with the gas lid off,and let the gas drain out into a pan or so.