Originally Posted by likebike23

Unless you are replacing the crank arm right now, I would stop trying to remove it. If it's just the pedal threads, and the pedal is falling out, could you find a piece of wood dowel or something to use as a "pedal" until you can get it properly fixed? Hammering on it could damage the frame or bottom bracket. If nobody has the correct tool and you are removing it for replacement, try riding around on flat ground with the fixing bolt out. The crank should come loose, just don't stand when you're riding.