http://wccftech.com/clean-install-tvos-11-gm/

Looking to clean install tvOS 11 GM on your Apple TV right now? We’ll show you how you can in a few easy steps.

Performing a clean installation of any firmware on a device has a satisfying feel to it. Not only the performance benefits are aplenty, but it also breathes a sigh of fresh air into your prized gadget. If you are an owner of an Apple TV 4, then things aren’t so different at all.