How to install the bits:
1. Swivel the bit holder and press the button. And make sure the button is pressed down.
2. Keep pressing the silver button on the nail drill, rotate counterclockwise to loose the bit holder.
3. Insert the bit and rotate clockwise to tight it in the bit holder.
Note: Keep the silver button pressing until the bit is inserted tightly in the cap. Please check the detailed installation video in the pictures section.