How do you change heater core in 1983 cutlass cruiser?

To change the heater core in a 1983 Cutlass Cruiser, start by disconnecting the battery and draining the coolant from the radiator. Remove the dashboard and the heater assembly cover to access the heater core, which is typically located behind the dashboard on the passenger side. Disconnect the heater core hoses from the engine compartment, remove any mounting screws, and carefully extract the old heater core. Install the new heater core by reversing the steps, ensuring all connections are secure and refilling the coolant before testing the system.