If you have passes to the MK...I would pay the fee to park there, if you have a car...or somehow get to the MK (whether you take a bus or drive, you'll have to go to the transportation and ticket center and then take the monorail to MK) then take the boat to Fort Wilderness. This drops you walking distance to Pioneer Hall, where the HDDR is. Afterward, then if you like you can take the boat back over to the MK and go in the park, or go back to your hotel.
This may sound like a round-about way, but IMO it is the easiest as I have found that it is difficult to get to Fort Wilderness because you have to take a series of buses (from Downtown Disney), even if you park there and to make it more confusing there is the Boone bus and the Crocket bus and one stops at all stops in Ft Wilderness and one is an "express" and I never know which is which...I think I recall this correctly...I also find it very pleasurable to take the boats. They are quite charming and relaxing.