How do I join my Apple TV to a different home?
I think you have to reset it to default and then set it up again as new.
Reset your Apple TV 4K or Apple TV HD
Go to Settings &gt; System &gt; Reset.
Choose a reset option:

Reset: This option is the fastest way to return your Apple TV to factory settings.  This option doesn't require an Internet connection.

Reset and Update: This option returns your Apple TV to its factory settings and installs software updates. This option requires an Internet connection.


Keep your Apple TV plugged into power until the Reset process finishes.
Source: Apple Support: Reset or restore your Apple TV to its factory settings