Valve Stem Extension Tutorial:
The only tool you’re going to need to accomplish this extension installation is a pair of needle nose pliers and the tire of choice or inner tube if it has a removable valve core.
The first step to install your extension is to simply remove the valve core of the tire or inner tube you’re working with. Sometimes you will need the pliers to break it free. Take the valve extender, the side with the threaded portion, insert it into the valve stem of your tube, take your need nose pliers and give it a quarter turn, just to make sure it is securely fastened. Pick up your valve core, and reinsert it into the end of your valve extender. Get it finger tight, then give it a quarter turn with the needle nose pliers, and now you’re ready to install your tire with the valve extension.