How do you replace a heater core on a 1992 Subaru Legacy?

To replace the heater core on a 1992 Subaru Legacy, start by disconnecting the battery and draining the cooling system. Remove the dashboard and the center console to access the heater core, which is located behind the dashboard. Disconnect the heater core hoses from the engine compartment, then unbolt and remove the heater core from its housing. Install the new heater core by reversing the process, ensuring all connections are secure and the cooling system is refilled and bled of air.