A pulley is a simple machine that is used to change the direction of a force in order to lift or move a load. Simple pulleys are formed with one pulley wheel and usually either rope or chain running around the wheel. One end of the rope is tied around the object to be lifted and the other end of the rope is pulled to lift the load. A double pulley system uses two pulleys to lift a load, which spreads the weight of the object across two pulleys instead of one, making it easier to lift the load.
Determine the weight of the load you need to lift.
Refer to the manufacturer's information for the pulleys to determine what weight the pulleys can lift. Use a single pulley if it is sufficient to lift your load. Use a double pulley or two single pulleys if one pulley is not sufficient to lift your load.
Run a rope (that is rated with strength enough for your load weight) over the pulley or pulleys. Use a long enough piece so that one end can be wrapped around your load securely and the other end can hang freely to the ground.
Connect one end of the pulley or pulleys to a sturdy structure that you will use as a lever, such as a tree limb or a bolt secured into a cement wall. The lever position needs to be higher than the level to which you need to lift the load. The pulley should have a hook or loop on its frame that allows you to make the connection.
Tie one end of the rope around your load so that it will be securely lifted.
Pull the other end of the rope to lift the load.