From Canada here,
you go to the app called Retail Mode. First password is the - 5444, then you will click off disable retail mode. will ask you again for password. that you will use the M729Q16K8546. It will then as you if you want to factory reset phone. Click yes.
Just did this on the Samsung Galaxy S6 Floor model phone that was given to me from a friend to make it usable.
will update if it's all said and done!