As I remember the best option is to head south on the "main drag" (535), pick up a donut and coffee at Dunkin Donuts, and then hop on the I4 south, getting off at the first exit towards Epcot. Follow the signs to the MK, MGM, or Epcot.
We tried taking streets past DTD but it took much longer. If you're in a big hurry skip the coffee and donut. ;-)