Where is the heater control valve on your 1988 Cadillac fleetwood d'elegance and how do replace it?

The heater control valve on a 1988 Cadillac Fleetwood d'Elegance is typically located near the firewall on the passenger side, connected to the heater core hoses. To replace it, first, drain the coolant from the radiator, then disconnect the hoses attached to the valve. Remove the mounting screws to take out the old valve, install the new valve in the same position, and reconnect the hoses. Finally, refill the coolant and check for leaks.