Take off the cable connector from battery's negative terminal. First take apart the radio from its position, then gently loosen the trim panel beneath the control panel with a panel removal tool. Unplug the control panel electric connections from the rear. Put a protective cover under the panel so that the center console area stays safe. Push the panel controls back into the dash, push the control panel out from the dash, and lower the assembly down through the bottom opening. To finish installing the control panel, you need to use a BMW diagnostic tool to teach the IHKA module what its job is once more. Have your BMW professional or experienced person take out the air conditioning refrigerant, then take the engine coolant. Uninstall the dashboard controls, the bottom steerable part of the steering wheel, and the instrument panel. Inside the engine area, take the heater hoses off at the firewall, stopping coolant overflow with shop towels or proper caps. Unscrew the bolts holding the air conditioning lines, then underneath the dash, take out the heater assembly mounting bolts from below the steering column, and loosen nuts at the left and right corners and screws from the center console of the heater assembly. Take the plastic supports out of the passenger section and gently pull down on the heater system to take it loose from the dash. Take off the bolts holding the heater box plate, disconnect electrical connections, carefully remove the heater core from the assembly, keeping some place for lost coolant to gather. We install just like we took apart but add new gaskets too before filling the car's cooling system after work is done. After discharging air condition refrigerant again, we remove the glove box, passenger compartment trim panel below the foot mat, and the screws from the current distributor in front of the blower motor to access the assembly. Free the plug connections by unlocking them and pulling them out. After that, remove the wiring harness and set it aside for now. Twist out the motor fan mounting screws, then carefully pull out the fan with its motor. Reinstalling goes step by step, just in reverse order. Unscrew the valve's cap next to the engine on the left-hand side; before and after opening it, open the expansion tank cap to let any pressure out of the cooling system. Then securely replace the expansion tank cap. Prevent coolant loss by clamping the heater hoses right near the coolant valve, disconnecting all wire connections, then loosening and disconnecting the hoses, removing the valve clips, and taking out the whole valve from the engine compartment. To put it back where it belongs, do the steps in reverse order.