First, unhook the battery negative cable and let the air bag system capacitor discharge for two minutes if the air bags haven't been set off. Take the driver air bag off of the steering wheel. Set the air bag housing into the slot at the back of the driver air bag cover, then carefully pry open the walls of the air bag receptacle to free twelve windows on the trim cover receptacle from the hook features on the air bag housing perimeter. Pull the housing, inflator, cushion and horn switch all at once from the driver air bag trim cover receptacle. Locate the plastic wire retainer keeping the horn switch feed pigtail wire in place, disconnect it, remove the nut and washer and pry the horn switch ground pigtail wire eyelet terminal from the leading upper left inflator stud. After sliding the horn switch and tray forward to free the retaining tab from the driver air bag retainer strap, pull the unit out to remove it from the pouch. Put the horn switch and tray unit into the pouch on the driver air bag cushion retainer strap so that they are installed correctly. Plug the open end of the horn switch ground wire through the clearance notch and select the eyelet terminal for the upper left inflator stud. Fit the nut and washer over the eyelet and tighten the nut to 7 Nm (65 in. lbs.) Push the horn switch feed pigtail wire through the clearance notch and secure the plastic wire retainer to the stud on the upper right inflator stud. Slot the air bag into the receptacle on the back of the trim cover and make sure you don't compress the air bag's wires, then fit each of the twelve hooks in the air bag housing through the trim cover holes. After connecting the hooks, push the blocking tabs and look at the air bag housing hooks to check if they are firmly seated. In the end, reinstall the air bag driver onto the steering wheel.