Take your vehicle to a dealer service or automotive air conditioning repair shop to empty the air conditioning systems. Take off the battery cable at its negative connection, using the needed security code when the radio comes with an anti-theft function. Disable the airbag if equipped. Drain the cooling system. Move the cable of the heater valve off its pin by prying it with a tiny thin screwdriver. Start by taking off the clamps from both heater hoses at the firewall, sliding hose plugs underneath the pipes to collect spilled coolant. Take off the heater mount nut above the tubes where the heater hoses connect, do it carefully so you don't accidentally damage the fuel lines or brake cables. On Integra models, you need to take out the passenger side part of the SRS beam. Unplug the control units for heater and air conditioning. Then take out the trim panel above the instruments, the base, and the entire instrument panel. When you don't have a working air conditioner, break the heater unit's connections where it meets the blower unit. If you have air conditioning, disconnect the
Evaporator unit while you work. Lift out the heater axis, disconnect the wiring bracket from the heater device, undo and take out the two nuts holding the heater unit against the bulkhead, and lift the heater unit off completely. Gently slide out the heater core by unwrapping the screws from its cover and clamp holding it down, then lift it out of its housing. Putting things back correctly requires checking the air control flaps work well and fixing any problems where parts stick before installing everything again. Add and release new liquid, reattach the battery power, make the motor run, look for leaks and see if the heating gets enough airflow. If your vehicle has air conditioning, get the system refilled at your car's dealer service department or an automotive air conditioning shop.