1. Go to https://www.orderbook.io/#/trading/
  2. Choose the needed trading pair. 
  3. Click on already existing buy order if you want your sell order to match with it and the amount of tokens you want to buy. 
  4. In case you want to set another price or there is no corresponding buy order at the moment, enter the price for one token. 
  5. After that click on “confirm”. 

Your order will be created after some time and will match someone’s sell order.