The batteries in the Beoplay A8 remote control are extremely long-lasting. When it becomes necessary to exchange them, you must unscrew the two small screws on the back of the remote control. Exchange the batteries with new AAAA alkaline batteries only.
Note that due to the low battery consumption, the batteries may expire before they lose their charge. This may cause the batteries to leak battery chemicals into the battery compartment. You must therefore make sure to change batteries before they expire.