How do you replace heater core in a 1988 Chevy Celebrity?

To replace the heater core in a 1988 Chevy Celebrity, first, disconnect the negative battery terminal and drain the coolant. Remove the dashboard and the center console to access the heater core housing. Disconnect the heater core hoses from the engine compartment, then unscrew and remove the heater core from its housing. Install the new heater core, reassemble the dashboard, and refill the coolant before reconnecting the battery.