Look at your most recent ESOP Individual Benefit Statement and review your current share holdings. Consult with your most recent company financial statement to find the per share value.
With your statement and expected share value available, call your ESOP representative. This person may be in your human resource department or an outside management company will initiate your sale transaction. Verify that your holding and share value match, or exceed, your most recent statement with the representative.
Your ESOP representative will take care of the administrative needs of the sale. You will likely have to sign forms accepting the terms of the sale. Once the transaction is complete, you will receive a check for the value of your sold shares.
You need to get a copy of the ESOP Agreement. It will spell out when you can sell, who can buy, how the terms are determined. If you don't have a copy, call your HR representative.