If the rod is simply on the crankshaft journal backwards, just unbolt it, push it up past the crankshaft counterweights, turn it half a turn, and bolt it back together. No need to remove the head. If the piston is installed backwards on the rod, no joy! Gotta pull the head!
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!