2002 S60 A/C Expansion Valve Replacement?????

[volvo]

I have a 2002 S60 T5 that the dealership says needs an expansion valve. The A/C compressor is turning on and off similar to a low freon but the freon if full and no leaks were detected. No other suggestions from mechanic and only suggested replacing the expansion valve. Anyone else had this problem and anyone know how to replace it.
Thank
Matt