We do not have specific information as to how to remove that unit.
That's the Steering Column Electronics Systems Control Module. It is not the main air bag control module. The main air bag module is sealed up and tucked away somewhere safe and sound in the vehicle. But, their are some controls for the steering wheel air bag in there.
That module is clipped into the steering column via two spring retainers but also has one bolt hidden in the front behind the actual steering wheel.
The following is directly from Audi service and repair.
Disconnect battery ground wire.
Observe airbag system safety precautions.
Remove the steering wheel.
Remove steering column switch module.
Remove bolt - arrow - (2 Nm) below spiral spring.
The Steering Column Electronic Systems Control Module (J527) is secure to steering column module with two spring retainers.
Release springs - 1 - and - 2 - with a small screwdriver.
I have given all the above information on the grounds that you are a seasoned automotive installer/technician and that this is not your personal vehicle.