First, we find out which exchange is trading this token (you can at coinmarketcap).
If you do not want to wait for the listing, and want to merge them as quickly as possible, then you need to forkdelta or etherdelta.
Selling tokens, we find an exchanger. If the currency into which you transferred coins is not supported by the exchanger, we translate it into another one, or we are looking for another exchanger.
There, on the exchangers, you already choose in which form you want to get your money.