Yesterday, I traded two of my broekn Xbox 360's to a man on Craigslist.
He then traded me a fully-functioning Xbox 360.
We traded, I told him ever problem that I encountered with the consoles.
He even referred me to his friend that will be fixing said Xbox 360's.
His friend said that it couldn't be done.
When the buyer arrived at my home, I told him that his friend said it couldn't be done.
Even with that information, he still agreed to the trade.
I told his friend that I would do a trade back if he couldn't get it to work.
His friend informed me that I couldn't make a guarantee like that due to a law in Arizona.

Now, the next day, he wants a trade back.
I don't want to do it now because I was reading articles about Craigslist scams and how people would take out things from the inside of merchandise. Sort of like giving you back the "shell."
So I don't know if I would want it back now.

So what should I do?
I am in fact a minor (15) so if I stopped replying to him I am afraid that he might come back to my home and take his Xbox back forcibly.
Additional Details
I wasn't around the bush when I told him the problem with the Xbox 360's.
I clearly stated that they have both have 3 red rings, and even gave him the secondary error codes on both consoles before we did the trade.