How do you remove harmonic balancer from 2000 kia carnival without a rattle gun?

Put a 21mm ring spanner on it, a block of wood under the spanner to the ground or to the suspension strut that goes across below the engine, then have someone hit the key to start the engine. DON'T really start it, just hit the starter so it will spin the crankshaft and the bolt will undo. Mine to about 3 hits of the starter to crack the bolt loose..