Either they disappeared her; or they had someone do it for them; or they literally put her out on the curb and shut the door. It's really down to these scenarios.
We know there are no back doors to 5 North, but it's only a few steps from their front door to get into a vehicle parked on 11th St. And of course we've discussed the duffel bag as carrier but it really is not necessary given that she was out on the streets incapacitated and no one was alarmed.
Re: your third possible scenario (that they put her on the curb and shut the door): It would be heartless, but it could also have ended in the same scenario Chuz Life mentioned. If LE had found her there, they might have traced her to JR. I suppose someone else could have found her, i.e., a random abductor. What horrific luck for LS if that was the case.
I've probably mentioned this before, but a guy I considered a friend left a girlfriend of mine passed out in a lawn chair on his front lawn one summer break. Nice, huh? I do believe he called someone to come get her (someone did), but it could have ended so badly in the meantime. So people like that are out there (grrrr).