We stayed at RP and walked over to the CB lobby one morning to look around. It took in the range of 15 minutes. The most direct route is to leave the lobby of CB, walk in the same direction towards the road that the taxis and buses use to enter and exit, then cross that road, note there is no crosswalk (which we found very strange) walking towards Sapphire. Walk through Sapphire entrance, then you have to go down the big circular stairs (or I'm certain there is an elevator somewhere close) to get to lower ground level, then go outside and down sidewalk past the boat launch towards RP, crossing another road just before RP. Then at RP you need to continue walking past the convention center and pool and then you have to either walk up two levels or take the elevator to the lobby and check in area.