MK your best bet is going to be the bus from the resort. Or at least that is the most direct.
Saratoga is right next to DS! If you are in the congress park section, you will be right next to the walkway to DS. If you are closer to the carriage house, there is a boat that leaves from behind the building that goes to DS as well!
At one point they also had a bus, and I believe they still do. Walking or boat are my favorites!