Q: How to remove and install a A/C Compressor in a Nissan Quest?A: To replace the compressor you also need to replace the accumulator / drier, as well as the orifice tube. First find an AC technician to discharge then recycle your current refrigerant. Then disconnect the negative battery cable, you then want to set the parking brake, and block the rear wheels, then raise the vehicle's front. Next you remove the drivebelt and disconnect the compressor clutch wiring harness as well as the high pressure switch connector. After that you disconnect the refrigerant lines and plug the fittings that are open. Now you unbolt and remove the old compressor itself. To install the new compressor, transfer the clutch from your old unit to your new unit. Make sure to add the correct amount of refrigerant oil to the new compressor based on how much you drained from the original. To install the compressor you do this in reverse, but using new 0-rings. Finally find an AC Technician again and have the system evacuated, recharged, and leak tested.