Disconnect the cable from the negative battery terminal. The left multifunction switch on the steering column controls the lighting and turn signals, while the switch on the right of the column controls the Wipe/Wash functions, including the operation of the rear wiper/washer on Armada models. Each switch can be replaced independently of the other. Remove the steering column covers. Press in the two clips and pull out the switch, squeezing the clips to release the switch from the column. Installation is the reverse of removal.