How do you remove a stuck gas cap on a lawn mower?

To remove a stuck gas cap on a lawn mower, first ensure the mower is turned off and has cooled down. Try twisting the cap counterclockwise while applying gentle pressure; if it's still stuck, use a rubber glove for better grip. If the cap remains stubborn, consider applying penetrating oil around the threads and letting it sit for a few minutes before attempting to twist it off again. If all else fails, a pair of pliers can be used carefully to grip and turn the cap, but be cautious not to damage the cap or the mower.