Turn off the snow blower. If the snow blower is part of a John Deere riding tractor, ensure the emergency brake is engaged.
Locate the slightly curved fastener piece of metal on the side of one of the tires. It will be just on the outside of the tire rim and have a hook on one end.
Grasp the fastener piece and lift the hook off of the connected chain link. You may have to push the hook forward toward the chain link then lift the hook out of the chain. The chains will loosen up.
Repeat Steps 2 and 3 on the other tires so that all chains are loose.
Lift the chains off of the tire. You may need to reach behind the tire and gently pull the chain off of the tire. If the chains become stuck or the weight of the snow blower is holding the chains under the tire, turn on the snow blower and drive/push it a few inches until the chains come free.