Have the air conditioning system evacuated by a properly-equipped shop. Disconnect the cable from the negative terminal of the battery. Drain the cooling system. If the coolant is relatively new, or is in good condition, save it and re-use it. Move aside the lower dash insulation to access the heater core pipes. Disconnect the heater hoses from the pipes protruding through the firewall. Plug all open fittings of disconnected lines to prevent entry of dirt and moisture into the lines. Disconnect the refrigerant lines from the evaporator. Remove the steering column. Remove the entire instrument panel assembly. Disconnect the connectors for various components. Disconnect the evaporator drain hose. Remove the instrument panel support beam and the heating and air conditioning unit as a complete assembly, and place the assembly on a work bench. Remove the heater core insulation to expose the heater core pipe bracket screws. Remove the heater core pipe bracket screws and remove the bracket. Slide out the heater core and remove it from the HVAC housing. Installation is the reverse of removal, noting the following: Do not use old O-rings for the refrigerant lines, replace with new ones and apply compressor oil to them before installation. When replacing the upper hinge bolts on the front doors, check the door-body alignment and adjust as necessary. Refill the cooling system. Reconnect the battery and perform the necessary re-learn procedures. Check for leaks and proper system operation. Check the operation of all electrical components of the steering column and dash. Have the air conditioning system recharged by the shop that discharged it.