How to use Apple TV without a working remote?
Download the Remote app for iOS onto a device with BTLE
Connect the Apple TV to iTunes and restore it (you will lose everything that's currently on the Apple TV)
Use the iOS physical tap method to set up the AppleTV and pair it to your iOS device
Profit in not having to order a replacement battery or replacement Apple infrared remote or borrow one to get it set up again.


Note, once you have the iOS app paired, you can train AppleTV to respond to buttons on third-party infrared remotes so you don't need Apple's remote going forward.