I just did about 2 weeks ago. Very very simple go to gate 52B and the shuttle starts running around 6:30pm there's a VA Rep there. The shuttle will take you to TBIT where all the VA flights depart now, however the Check-in desk still at T3. even if you don't have a boarding pass you can still get on the shuttle if you can prove them you're transferring to a VA flight. No other airline can use the shuttle.