The above video from NCPTT will cover the basic procedures for lifting a headstone using a hoist. Some stones are just to large and heavy to move without a lift. Using a lift can be very dangerous, always use caution and exercise personal safety and try to do no harm to the monument itself, they are very delicate and can easily break when being moved around.
There are many types of lifting systems to use, from very complex cranes and truck mounted hydraulic booms to less complex gantries and tripod hoists. In this video you will see a readily available tripod hoist being demonstrated.
When picking out a tripod hoist check the load rating. It is important to know if the stone you wish to move is within the limit of your tripod hoist.
Below you will find some options of tripod hoist and other items you may need, click on picture to buy.