Unless instructed otherwise, here is what you will do at most attractions:
1)Tell the TM at the front you're doing child swap. They will either have everyone go through line, or have everyone who is riding first go through line while everyone who is waiting goes up the exit to the waiting area.
2)Tell any TMs along the way (if applicable) that you're doing child swap. Those that are going to ride first will be directed on to the ride, while the non-riders will be sent to the exit.
3)The riders ride the ride. When they exit, they either go directly to, or can ask for directions to the child swap room. The rooms are usually very close to the loading area.
4)Those that waited then go to the loading area and inform the TM that they did child swap. You can usually take a few of those that rode with you if they want to go again (usually 1-2). Those that waited then get to ride without having to wait in line again.
5)After finishing the ride, everyone can meet wherever you want and continue on your day.