One of my relative left US permanently and is in another country now ,he says he still have some money in the US stocks ,how can i help him to get that money or do he need to come here in order to sell his stocks? I have zero knowledge about stock market and how it works ,I would like to hear some serious suggestions.

Sell the stock online and wire transfer money into checking.... Shouldn't be a problem

@i485 tx for the info ,but can i sell his stocks and transfer money in my a/c or not? 

If you sell your stock, money will be depisited into you bank. But not sure you can do wire transfer, unless you have set up it earlier.  Last time I went to my local bank for wire transfer: Needed to be present  with positive photo ID.
Best way: write a check to you friend and ask him or her to wire you.

Sell the stock and have the money transfered via ACH or wife transfer. If that doesnt work you can ask the Broker to mail you a check. You may have to ask your relative to call the Broker otherwise they are not authorized to give it to you.