how do i change the batteries in the Apple TV remote?

The Black remote for. Apple TV HD and 4K does not have removable batteries. If it battery is low, you plug it ion with the included Lightning cable into a USB port on your TV or an iPhone or iPad charge to charge.

The silver remove for Apple TV 2nd and 3rd generation, has a panel on the back you can twist open with a coin or flat screen driver to access the battery.

Which Apple TV remote are you refering to? Perhaps this will help you Identify your Apple TV model