How do you change the heater core on a 1998 Chevy Cheyenne?

To change the heater core on a 1998 Chevy Cheyenne, start by disconnecting the battery and draining the coolant. Remove the dashboard and the center console to access the heater core housing. Disconnect the hoses and any electrical connections, then unbolt and remove the old heater core. Install the new heater core in reverse order, reconnecting everything and refilling the coolant before testing the system.