I have a 1999 ML320 that the drivers door inside door lever quit working. To determine the problem I must remove the interior door trim. What steps must be taken to ensure that the side air bag does not deploy?

The inside door lever swings freely. It either came disconnected from the rod or the rod holder broke. Opens fine from the outside.

I removed the driver side panel from my '96 W210, and while it's undoubtably quite a bit different, the airbag itself was attached to the door frame. There was no need to do anything with it or its wires, so I did not disable it.

If you are in the same position, just don't touch it or its wires. If you do need to disable it for another reason, you need to unplug the controller itself, not the airbag. I have no idea where that might be on your vehicle.

the air bag is riveted to the door, if you are not going to remove the bag there is nothing you need to do, to acess the inside door handle you normally do not need to remove the bag. if the door latch mechanism needs to be replaced you may need to remove it.