[Hatredcopter]

You can do an exchange in high school, but I'd recommend doing it during college... it's more beneficial.

Most exchanges are coordinated through schools. You'll have to ask an adviser or counselor at the school you go to if they have any exchange programs. Otherwise, there are third-party organizations that run exchange programs... they're generally quite a bit more expensive than if you were to go through a school's program, though. I don't know any names off the top of my head, because I went through my school, not a third-party program.