Better I think to use the so called Gibbons method to change the oil in the transmission. the repeated fill and dump method is tedious, and also its a bit like closing a door one quarter of the way, then closing the remaining distance one quarter etc., never get the door closed, and by inference, never get really clean oil into the gearbox that way either, and you would use more oil to achieve a lesser result. Always good to do the transmission counter reset using Vida / Dice once you are done.
Also a good idea to check the oil condition in the angle gear, diff and the Haldex unit while you are at it.
The other thing is that the oil level in the auto transmission is set once the gearbox has reached an operating temperature of 60 degrees C if I recall correctly. This can be easily monitored using the Vida / Dice setup.
Good luck with it.
