"Hey, dude? Your 360 broke. Don't test it, just trust me. But I'll give you mine if you give me yours. Cause, y'know, yours is broke. No trade-backs though! And no, you can't check it, it's broken. Seriously. Trust me man. No trade-backs."

You fake the RDOD so that it breaks but you know how to fix it.

How would one go about doing that?

Open the xbox when he is not home and unplug the fan or just stick something in the fan to get it working properly and it will cause it to over heat after a while. You can also tamper with the power brick to cause a RROD.

so then I have an xbox with a RROD...

I think the end result is supposed to be that you can then send it in to get repaired/exchanged free of charge. However, I'm rather doubtful that the techs wouldn't notice that it had been opened. I mean, after five years, I think they'll be wise to at least most of the tricks people pull.

I'm pretty sure that wont work. I was trying to do that to my old 360, but apparently even though RROD is the "general" error, the system still documents what happens. Most of the time forced RRODs are one deal things - at the repair centre, the system must consistently display the RROD, other wise they'll just mail it back to you.