What you need to remove the airbag is about a 3" long T30 Torx bit, and the driver for the bit (1/4" driver) and a 1/4"drive ratchet.
MB sells the bit (PN 126-589-10-00), but you can probably buy it elsewhere.
There are small holes in the back of the steering wheel, the long bit is inserted into these holes to remove/loosen the 2 screws holding the airbag to the wheel.
"Every precaution" would seem to include removing the negative battery terminal before removing the airbag. I've never done it and never a problem. If you turn on the ignition switch with the airbag disconnected, you WILL have an SRS warning light later, which will need to be cleared.
You then will need a 10mm(?) allen socket to remove the bolt holding on the steering wheel, although after removing the bolt the wheel will pull right off the shaft, no puller needed.
At this point the steering wheel angle sensor/horn contact spiral needs to be removed. Before removing the steering wheel, make sure the steering wheel is centered (straight ahead position). With the wheel straight ahead, it opens up 2 holes in the horn contact spiral so they are directly over the corresponding screws. DON'T force the contact spiral around, you will ruin it. Remove the 2 screws and pull off the spiral. You can then access the combination switch and/or cruise lever.
Rich, at this point you can tighten the 3 screws holding down the combination switch, this will fix your problem, seen that alot.

Gilly