Q: How to Replace an Automotive Air Conditioning Compressor?A: Have a technician discharge and recover the AC system's refrigerant. Disconnect the battery and raise the vehicle on jackstands. Remove the compressor's drivebelt, and disconnect the electrical connector and refrigerant lines. Seal the ends, unbolt and lower the compressor. If installing a new compressor, follow the oil level instructions. Installation is the reverse of removal. Replace and lubricate any 0-rings with refrigerant oil. Have the system evacuated, recharged, and leak tested.