Start the engine, leave it in park, and set A/C to maximum cold position. Shake well. Attach the hose to the can with retracted piercing valve. Attach the other end to the suction port. Unscrew can slightly to remove air. Retighten can turn upside down (valve down), then puncture can with piercing valve. Allow 1-2 minutes for installation. Close the piercing valve and remove the hose from the suction port. Reinstall the port cap. Leave can attached to hose until next installation to prevent contamination. All used and unused products must be disposed of in accordance with federal, state, and local regulations.