First of all, you should call to your broker and sell your common stock shares through the standard brokerage. This is a bit expensive as you have to pay the commission but the good thing is that the money will go directly to your account.
However, the better way is to open an online brokerage account and sell your common stock shares online. You can hire a full time service broker who will cost you much less as compared to the commission you normally pay to a broker of a standard brokerage firm.
A full service broker will help you in placing conditional orders, stops and all other relevant actions. Your online broker will also help you in research which will enable you to anticipate the prospects of your shares in upcoming days.
You should sell your common stock shares when the price hit a protective top. Do not delay this process as it can get down in the next hour. So, you have to be a strong decision maker in order to get maximum benefits from your common stock shares.
If you anticipate that the value of your common stock shares will decline in a few days, then you should sell a small part of your shares. It will also help you in learning the techniques of trading in stocks.
Do not sell all of your shares by anticipating a decline in value as sometimes anticipations go wrong and people face bigger losses.