Mears do a shared shuttle van between Universal and all Disney hotels, including DAK lodge, for $21 per person for a return trip. You just phone them up to request a pick up and they'll give you a time. They go to several hotels on the way depending on who has requested a pickup so it takes longer but is definitely the cheapest way to get there and back if you don't mind riding with other guests.
If you need to rent a car the Alamo by Magic Kingdom gives good service and a driver will come and pick you up from your hotel to take you to the rental counter.