Once you've pulled the syrenge back, hold it up straight with the needle in the air. Then flick the syrenge with your finger until the bubbles start move up to the top. Keep doing that until all the bubbles are at the top and formed one large bubble. Then slowly push that bubble out by pushing on the handle of the syrenge. As soon as u see a droplet of juice come from the head of the needle, u can stop. Then inject!