How do you replace a heater core in a 2003 SS Monte Carlo?

To replace the heater core in a 2003 SS Monte Carlo, start by disconnecting the negative battery cable and draining the coolant. Remove the dashboard and center console to access the heater core housing, followed by disconnecting the heater hoses and any electrical connections. After removing the bolts securing the heater core, carefully extract it from the housing and install the new one, reassembling everything in reverse order. Finally, refill the coolant, bleed the system, and reconnect the battery.