You start by removing the little gray cap over the led. Then, you carefully take out as much stuff as you can from that end (it is better if you wear the battery down to no charge first). You then have to get the connector off the other end - this is the hard part. If you have an extra charger you don't mind messing up or a dead atomizer, you can screw it onto the battery and wiggle forcefully until it comes loose from the battery casing - sometimes they are glued and pressure fit, other times they are just pressure fit. Madog makes it look easy, but it does take a little strength and determination.