I did this successfully and then switched back, but the initial change to Mexico said it "unlinked me from my Nintendo Network ID"
I can't remember how to relink it (if I even care to as I don't even remember what this does)
Edit: Nevermind, I found where to relink it =)
My wife redeemed a code for this song already and I wasn't aware, so I have an extra code. If anyone has a song to trade, I'd probably go for it.
30 Seconds to Mars