Put a face mask on to protect your lungs and wear goggles to protect your eyes. When you knock down the wall, bits of debris and dust will be in the air.
Insert a wedge into a crack in the wall and hit it with a sledgehammer to begin breaking the rocks apart. Start at the top of the wall and work your way down. If the rock wall stands alone, nothing will be behind it. If it abuts a hill or other land, however, you will likely find wood or concrete behind the rocks.
Remove stubborn rocks by using a chisel and hammer to break away the cement around their base.
Use a crowbar or the claw side of a hammer to pry away any wood that supports the wall. You may also find concrete, which can be removed with the sledgehammer.