How do you replace the heater core in a Jeep Comanche?

To replace the heater core in a Jeep Comanche, start by draining the coolant and disconnecting the negative battery cable. Remove the dashboard and the heater assembly, which may involve taking out several screws and bolts. Once you have access to the heater core, disconnect the hoses and remove the core from the housing. Install the new heater core, reassemble the heater assembly and dashboard, and then refill the coolant before testing the system.