How do you add refrigerant in Oldsmobile Regency 98?

To add refrigerant to an Oldsmobile Regency 98, first ensure the vehicle is off and locate the low-pressure service port, usually found on the larger diameter aluminum line. Use a compatible refrigerant, typically R-134a, and connect the charging hose to the port. Start the engine and turn the AC to maximum to allow the system to run while you slowly add refrigerant until the pressure gauge reaches the recommended level. Always check for any leaks and ensure proper safety precautions are followed.