TweetI just put on the drawing needle and pull the plunger back to get air in it. Next I stick the pin in the 1st bottle and fill it with air. Then I take the pin out and pull the plunger again. This time I put it into the 2nd bottle shoot air in it and withdraw my precious. Since you already have air in the 1st bottle stick in the pin and withdraw. Hope that makes sense- crombie09