How to a change heater core on a 1988 Lincoln mark 7?

To change the heater core on a 1988 Lincoln Mark VII, start by disconnecting the negative battery terminal and draining the coolant. Remove the dashboard and any components blocking access to the heater core, such as the center console and HVAC housing. Disconnect the heater core hoses, remove the heater core from the housing, and install the new core. Reassemble everything in reverse order, refill the coolant, and check for leaks.