You can change the air flow direction via the climate view in the centre display or physically using the air vent knobs on the air vents.
To open the air vent, turn the physical air vent knob. This allows the air to flow.
Redirecting air flow via the centre display
Press the fan symbol 
in the bottom bar.
in the bottom bar.Press the air flow symbols to select your preferred air flow direction.
Redirecting the air flow physically
Move the physical air vent knobs to redirect the airflow.
Tip
If you choose a specific air flow direction in the centre display while auto climate mode is active, the climate system will change to manual mode. You can always go back to auto climate mode again by selecting Auto in the climate view.