Disconnect ground cable from battery. Drain coolant from radiator. Disconnect heater hoses from heater core. Cap heater hoses.
Remove bolt, located below windshield wiper motor attaching left end of plenum to dash panel. Remove nut retaining upper left corner of evaporator case to dash panel.
Disconnect control system vacuum supply hose from vacuum source and push grommet and vacuum supply into passenger compartment. Remove glove box.
Loosen right door sill plate and reomve right side cowl trim panel. Remove bolt attaching lower right end of instrument panel to side cowl.
Remove 2 screws attaching instrument panel pad to instrument panel at each defroster opening. Remove screw attaching each outboard end of pad to instrument panel.
Disengage temp. Control cable housing from ATC sensor. Disconnect vacuum connector from ATC sensor. Disconnect electrical plug from ATC servo plug.
Disconnect ATC sensor tube from sensor and evap case connector. DIsconnect vacuum harness at multiple vacuum connetor near floor air distribution duct.
Disconnect WHITE vacuum hose from outside-recirculation door vacuum motor. Remove 2 screws attaching passenger side of floor air distribution ducto to plenum. May be necessary to remove 2 screws attaching lower panel door vacuum motor to mounting bracket to gain access to right screw.
Remove the plastic push fastener retaining floor air distribution duct to left end of plenum. Remove floor air distribution duct.
Remove 2 nuts from 2 studs along lower edge of plenum. Remove plenum assembly. Remove 4 retaining screws from heater core cover. Remove cover.
Remove retaining screw from heater core inlet and outlet tube bracket. Remove heater core and seal assembly from plenum assembly.
Reverse removal procedure to install.