How do you remove heater core on 1971 Pontiac lemans?

To remove the heater core from a 1971 Pontiac LeMans, start by disconnecting the battery and draining the cooling system. Then, remove the dashboard to access the heater box, which typically involves taking out various trim pieces and fasteners. Once you have access to the heater box, disconnect the heater core hoses, unbolt the heater core from the box, and carefully remove it. Reverse the process to install the new heater core, ensuring all connections are secure before reassembling the dashboard.