Following manufacturer's instructions, connect an approved refrigerant recovery, recycling, or recharging unit to the NC system and discharge the system. Raise the car and support it safely, then remove the splash shield from under the engine. Mark the A/C drive belt with the direction of rotation and remove it. Working above the right front of the engine compartment, squeeze the plastic junction at the secondary air valve to separate the air intake hose and tie it to the side to gain access to the NC compressor. Disconnect the electrical harness connector from the NC compressor and remove the refrigerant line flange bolts from the compressor. Immediately plug the lines and ports to prevent contamination, then support the compressor while removing the mounting bolts and take out the compressor. Depending on the model, the compressor may be mounted with three or four bolts, and installation is the reverse of removal. Replace sealing O-rings when reconnecting refrigerant lines, and if installing a new compressor or if the compressor is off the vehicle for more than 24 hours, replace the receiver-drier unit. Install and tension the A/C drive belt, noting the previously made direction mark, and recharge the A/C system following the equipment manufacturer's instructions, checking the refrigerant capacity. When starting a new compressor for the first time, switch the A/C system ON, set air vents to OPEN, start the engine and allow it to idle, set blower output to 75% of maximum, and run the A/C for at least two minutes at idle speed (under 1500 rpm).