Just take the core out of the valve stem. It will deflate safely. If the thing didn't hand grenade when it was aired up originally, the pieces of the rim locked together properly. Of course, it you've got a flair for the dramatic, just prop it up at the local rifle range and deflate it from 100 yards away with a .30-06! The tow company operator who trained me to recover wrecked 18 wheelers had a good method of deflating tires on crash-damaged wheels- - - - -he used a 1911 .45 automatic with full metal jacket ammo!
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!