Transfer of shares on closure of company

Hi,

We are in the process of closing down a private limited company. It is a small company with paid up capital of Rs.1 lakh. 80% of the shares are held by the promoter and the balance 20% are held by employees of the company. Some of the employees have left the company.

Please guide as to the process  to be followed under companies Act for taking  back the 20% of the shares held by the employees and ex employees