Put the pipe in furnace and gather the glass. Put one end of the pipe in the furnace, holding the pipe straight. You may need an assistant to open the door of the furnace for you so you can put in the pipe. Then, roll the pipe around in the furnace to gather the glass. You want to get as much of the glass on the pipe as you can so you have a lot to work with.
You can try to open the furnace door yourself if you do not have someone to assist you, but it may be tricky to do if you are beginner glassblower.