How to change a heater core on a 1989 riviera?

To change the heater core on a 1989 Buick Riviera, first disconnect the battery and drain the coolant. Remove the dashboard and HVAC housing to access the heater core, which is typically located behind the firewall. Detach the hoses connected to the heater core, and then remove the mounting screws to take out the old core. Install the new heater core by reversing the process, ensuring all connections are secure before reassembling the dashboard and refilling the coolant.