Can't figure out how to begin the Safecracker game for Wii?

I recently bought this game, but I can't seem to figure out what to do first. I've explored all three original rooms, but found nothing more than two bolted doors and two safes. I also located one letter which seems unhelpful. Anyone else figured out what to do first?Can't figure out how to begin the Safecracker game for Wii?
the answer is in the safe

ie tab