How do you replace heater core on 97 Cadillac Seville?

To replace the heater core on a 1997 Cadillac Seville, first, disconnect the negative battery cable and drain the coolant. Remove the dashboard and the center console to access the heater core housing. Disconnect the hoses and any electrical connections, then unbolt and remove the heater core from the housing. Install the new heater core, reassemble the components, and refill the coolant before reconnecting the battery.