Q: How to remove and install a heater core in a Pontiac Firebird?
A: Disconnect the cable from the negative battery terminal. Drain the cooling system. Remove the heater hoses from the heater core inlet and outlet pipes. Use care in removing the hoses so as not to damage the heater pipes. If necessary, cut the hoses off the pipes and replace them with new ones. Remove the lower insulating panels from under the left and right side of the instrument panel. Remove the instrument panel pad. Retaining screws are located in the defroster vents and along the underside of the rear edge of the pad. Remove the retaining nuts to both front speakers and remove the speakers. Also remove the right speaker bracket. Remove the screws retaining the side window defrost ducts, the front carrier braces and carrier shelf, and remove the side defrost ducts. Carefully disconnect the Electronic Control Module and set it safely aside. Remove the radio trim plate, the upper console trim, and the glove box assembly. Remove the parking brake handle grip, the screws retaining the console body, and position the console back out of the way. Remove the trim plate under the steering column. Remove the two nuts retaining the steering column and carefully lower and support the steering column out of the way. Remove the bolts/nuts retaining the instrument panel to the cowl. Move the instrument panel back far enough to access the heater module and remove the heater module cover. Remove the screws retaining the heater core shroud to the module and withdraw the heater core from the module. Installation is the reverse of removal. Replace the seals with new ones. Refill the cooling system and test for leaks.