When we were there, we had someone in our party who could not walk very much. The bell staff at the HRH were kind enough to take us in the hotel's van. They left us with a phone # to call when we wanted to be picked up.
If mobility is not an issue you could take the water taxi from PBH to CityWalk, then take another water taxi to RPR. The stop at RPR is right in front of Tchoup Chop.