Changing UOM from Carton to Pieces

Hi Gurus,

My client has configured his material's UOM as CAR and now he is asking me to find a way to be able to sell that material in pieces (28 pieces = 1 carton). System says PC is smaller that UOM (CAR). How to manage sales in Pieces? There is a lot of stock of that material and a lot of pending sales orders / production orders / delivery docs. Is there any way to do it??

Thanks in advance.

Regards.

Venkat