Two more points -
The MB 124 manual requires the connector to the airbag be removed before the airbag is removed from the wheel. Simply disconnecting the battery is not sufficient to insure the airbag does not fire. Remove the front passenger side carpet. Remove the false floor at the front of the passenger footwell. Underneath there is a bright red electrical connector - it's the only red one on the car. Unplug it.
Also, the torx screws which retain the airbag to the wheel are tamper proof. You will need to obtain a set of tamper proof torx drivers to remove it. I have no idea where to acquire such tools - I'd kinda like to have a set myself.