While Klaus' advice is solid and right out of the book, nobody that I know disconnects batteries while working on the SRS. Make sure that the key is in the off position BEFORE you pull the plug out of the back of the bag and do not turn the key to the on position at anytime while you have it disconnected and you will have no issues.

Remove the two torx head screws that go in through the back of the steering wheel into the bag, they are located at the 3 and 9 0'clock positions, set the steering wheel so it is flat and straight, make sure that the key is off, pull the bag out, pull the plug out of the bag, install the screw that will lock the spool reel (clock spring), remove the bolt that holds the wheel on, remove the wheel. If you screw up and turn the clock spring loose it is not the end of the world, just center it back up and it will be fine.

Mark