You can email them, and then send a hard copy trying to be respectful. Also, I think that you should put a P.S. stating that I should be given your spot off of the waitlist
HAHAH dude what if I actually did this. Since I am no longer interested in the program I could just add a little PS note at the bottom saying "PS: I would like to recommend funkydrmonkey (a poster on the Student Doctor Network internet forum) as a fine candidate to take my place. He accepts PMs"