Instruction for installation: Pull out the used glass mouthpiece from the whip tubing. Be careful not to crack the glass. If the mouthpiece is cracked or broken, take extra caution to extract the glass from the tubing. After extraction of the mouthpiece, put the new mouthpiece into the tubing. If the new mouthpiece does not fit easily into the tubing, try dabbing both end into water to lessen the friction.