| Steering Wheel Swap, step by step
Okay, folks, I finally got around to changing my W210 steering wheel. This basic procedure is the same for pretty much all of the newer MBZ vehicles with airbags.
First, a few caveats. Remember that this is a basic procedure, but not for the faint of heart. Make a misstep and you could end up with a mess. Second, be prepared; once you have the airbag assembly off is not the time to find out you don't have the tool necessary to pull the retaining bolt. Third, take your time; no sense in rushing. Last, be sure you have your owner's manual and radio code handy.
STEP ONE. Bring the steering wheel to almost center, I left it slightly left as you can see in the photo to permit easier access to the left airbag assembly bolt. Extend the steering wheel from the dash as far as it will go.
STEP TWO. Disconnect the negative lead from the battery. You can access the lead from the snap-off cover in front of the right-side rear passenger seat. It's a 7/16" nut. Be sure you have unlocked all doors and that the key is in your pocket. Close the door to extinguish the dome light, then remove the nut and pull the lug off the terminal end. I stuck the plastic cover halfway back in to ensure the cable lug wouldn't drift back over and make contact.
STEP THREE. Loosen each of the airbag assembly retaining screws. They are T30 Torx, but you can use an allen wrench if you desire. Although I had torx sockets, the hole provided is too small for anything other than a straight-shaft tool, so I ended up using a 5/32 allen wrench and a cheater to get enough torque to loosen these screws. Once each of the screws is loose, go ahead and completely loosen them. They will remain in the steering wheel, so you'll have to periodically pull on the airbag assembly to see if you're finished loosening them. | 
