Register the Remote with Another Device-
Often there’s no need to remove a remote’s pairing. If you get another Fire TV, all you have to do is pair the remote with it and everything will automatically switch over. Remotes can only be paired with a single device at once, so the Fire TV OS handles it pretty well. •
Manually Un-pair a Remote-
A somewhat hidden feature is the ability to force unpair a remote. If Fire TV doesn’t offer a menu option to remote an accessory, all you have to do is go to Settings > Controllers & Bluetooth Devices > Amazon Fire TV Remotes and highlight the device in question. Then, hold menu + back + home for 15 seconds. When the unpairing completes, Fire TV will send you back to the main menu.
Remove Paired Remote Apps-
A strange quirk of the Fire TV interface is you can’t actually remote a paired remote app once it has been initially paired. If you run out of pairing space, the only way to get rid of them is to factory reset your Fire TV device.