Instructions
Locate the information for a coin dealer near you. This can be found in a phone book. Finding an email address and phone number are important so you do not waste your time driving around to various coin dealers and collectors.
Email a picture of your coin to several of the stores' email addresses. Include relevant information about it (i.e. official certificate, how it has been stored, etc.). Ask how much you would be able to get for the coin.
Wait for the responses and compare the prices. Barter with the dealers quoting other prices you have gotten. You can over-quote, but not too much. They will know what price is too high.
Decide who you are going the sell to and go to the shop. Exchange your coin for cash.