Unfortunately you cannot sell the stock without a stock broker. Where are the shares being held currently?
The easiest way to go would probably be to open an account with a discount online broker, have them add transfer your shares to your account, then sell them that way. You can find a full stock broker comparison chart here on our site,
http://www.stocktradingtogo.com/stockbrokers.html. Going with a broker that has local branches might be the best route so you can talk to someone live. Scottrade in that sense (see the page for details) might be a good fit.