Nothing could be easier. You ahve a lot of options. The fastest is to walk over to the TTC, then bus to Ft Wilderness. You could also, alternately, monorail to the Contemporary or the MK to catch the boat at either one. Keep in mind that the MK needs to be open late in order to catch the boat to and fro; and the boat from the Contemporary to Ft Wilderness stop srunning at 10.
Either way, on your way back you'll need to bus from Ft Wilderness back to the TTC.