1.) Unlock the Padlock E and pull the shackle to open position.

2.) Turn Torx cap  clockwise 120° with the Torx screwdriver & push battery cover out.

3.) Replace the CR2 battery, close the battery cover and turn Torx cap counter-clockwise 120°.

4.) Push the shackle to close position to lock it via Auto Lock or manual relock.

NOTE: 

Ensure that you align the battery markings as not doing so will result to damaging of your padlock E!.