Keep the pump hooked up so fluid will be available for lubrication, but remove V belt that drives pump. Car will steer real hard, and almost not at all when stopped. Also if fluid is too high in tank, some will be displaced on the ground when turning steering wheel when pump is not pumping, but will stop puking when sufficiently lowered.
Driving a power steering car without the assist working is dangerous and pretty hard on the steering box. In an emergency you don't have a choice, if it's sitting in the driveway, leave it there until you can fix it.