How do I reset my Apple TV

Welcome to the Apple Community.

Try the following steps for the Apple TV 2 & 3,

1. Reset the Apple TV (Settings ➔ General ➔ Reset ➔ Reset all settings)
2. Restore the Apple TV (Settings ➔ General ➔ Reset ➔ Restore)

Try the following steps for the Apple TV HD & 4k

1. Restore the Apple TV (Settings ➔ System ➔ Reset ➔ Reset and Update)