We've found the easiest is to use Disney buses to go to Downtown Disney, then hire a taxi cab to go to the Orlando Premium Outlet. It will run about $10 each way, but since you will 'fill' the cab with family members, it will be a very reasonable cost for a direct shot to the outlet mall. It's a nice break from the parks. Hope your teens enjoy it.
Oh, and another thing...remember you are in Orlando and be cautious. Shopping tourists can be a target. Once when we were there someone got shot. Like any city, ALWAYS be aware of your surroundings.
Snoop