If for some reason you can't get the transmission out of P (most trans have a cosmetic plug near the shifter you pop off and use a screwdriver to unlock the shifter), you could get some car dollies and place under each wheel.
https://www.harborfreight.com/2-piece-vehicle-dollies-67511.html
https://www.harborfreight.com/2-piece-vehicle-dollies-67511.html