In Canada, you would have to be working @ a BMW dealer to be sent to FACTORY BMW training as I did while I was working for BMW. They have a factory training facility @ BMW Canada.
So basically to become a BMW trained tech you would have to first get into a BMW dealer, then its up to the service manager to send you for training if they want.
Or you could get a job @ a good indipendant shop that works on BMWs and learn about them.