Guys, you need to press and hold LShift+A to override the autopilot, set the desired pitch and roll settings and then release LShift+A. The autopilot will take in the new settings and fly it accordingly. Also, use the Autothrust feature (J). The autothrust can be increased (LShift+J) and decreased (LAlt+J) accordingly. Using these settings, refueling is very easy.