To replace a vehicle's air bag, disconnect the negative battery cable, remove the air bag fuses, remove the part of the car covering air bag, unplug the old airbag and insert the replacement. The actual procedure for uncovering the airbag may vary depending on the vehicle make, model and year.
Most newer vehicles have multiple air bags to protect passengers in various crash scenarios. These air bags are located in different places that include front driver and passenger locations, side torso, side curtain and knee units. Other possible locations include the rear curtain and center console. The procedure for removing the part of a car that is covering the specific air bag that needs to be changed is different on almost every vehicle. Vehicle repair manuals from companies such as Haynes or Chilton can provide specifics.
After disconnecting the battery and the fuses, remove the steering wheel cover, dashboard or appropriate panel to access the air bag. Unplug the electrical connection behind the air bag in the back of the recess, and remove the bag. Plug the new air bag in, and gently fit it into the recess. Replace any panels, covers or plates that you had to remove to access the air bag. Reinstall the fuses, and connect the battery.