With a 993 Carrera 4 S it´s an easy job. You just have to lock the steering to one side while running and than use the hand brake to let the rear end brake loose, and as soon as the the rear tires slide a bit, you give full power with the steering lock , the car spins and makes several donuts in the same place, it´s great to see from outside and even better to feel inside
Haven´t you seen the way Tiff Nedle brake loose the rear tires? He´s using the hand brake to do so.
Maybe in the 4S Porsche it´s easier because you have more power on the rear wheels than on the front, so the the rear keeps spining all the time.