Amazon Prime Video App

We have 2 TV's in the house.  one attached to the DVR and the other connected wirelessly.  We had a house guest who added his Amazon Profile to the wi-fi TV. and now we are prompted for his PIN, anytime we pull up that app on that TV.  Our TV that is connected to the DVR, still has our Amazon profile, but the other TV has his.

Does anyone know, how I would reset where the wireless TV is getting its Amazon Prime app profile?