How do you hang drywall over plaster of Paris?

Paster of paris is a form of drywall, so I'm unclear on your meaning except possibly you have a wall with plaster over lath and want to cover it with drywall. You can find the studs electronically and go ahead and attach drywall to the face of the plaster with extra long screws. - Personally, I would rather repair whatever is wrong with the plaster and lath.