How do you replace a heater switch on a 1999 Jetta?

To replace the heater switch on a 1999 Jetta, first disconnect the negative battery terminal to ensure safety. Then, remove the trim around the center console and carefully detach the existing heater switch by unscrewing it and disconnecting the wiring harness. Install the new switch by connecting the wiring and securing it in place, then reassemble the trim and reconnect the battery. Test the new switch to ensure it operates correctly.