From GF, get on the monorail on the second floor of the lobby, get off at the Ticket and Transportation Center (TTC) and transfer to the Epcot monorail. From BLT, walk to CR, get the monorail (escalator to the monorail is on the 4th floor), get off at TTC and transfer to the Epcot monorail. If all runs smoothly, it will be around 35 - 45 minutes.