It’s a pain in the butt. On one of the sides, you will see a little tab sticking up. Holding the button so that the little tab is on the left, slide it to the right. After this, the best think I found was to grip the sides and make the motion like you were packing new cigarettes but don’t hit the device on your palm. You can also use a small knife to pry it out after pushing the tap to the right but you risk damaging it. Seriously it’s just a big pain in the butt.