How do you change a heater core on a Lincoln mark VI?

To change the heater core on a Lincoln Mark VI, first disconnect the negative battery cable and drain the coolant from the radiator. Then, remove the dashboard and the center console to access the heater core housing. Disconnect the hoses from the heater core, remove the screws or bolts securing it, and replace it with the new unit. Finally, reassemble the dashboard, reconnect the hoses, refill the coolant, and check for leaks.