"Why not start with some swaps" you can always swap them back later. The labs were closest anyways.
The labs are a bit foreboding. Labs always sort of crept you out. Even seeing a hospital while walking through the city could be awkward.
You look down into one of the exchange rooms. It looks like someone is giving up her arms to someone with far to many arms. Some people donate parts instead of swapping them. Arms sounds a bit excessive though.
You go up to a friendly looking guy and start to talk, "hey..."
"Hi!" He replies.
"Are you here to swap?"
"Yeah, first time, just turned 18. The names Alex by the way."
"Same"
This is it, he could be your first swap. You nervously say, "hey, want to swap with me, I'm not sure what I want to you can just choose."
He smiles, "hey, you know there's something I always wanted from a girl."