Apple tv app
How can I change the apple tv user and password
FireTVStick4K,
Question marked as
You can reset the Apple TV app, and sign in with a different Apple ID account.
You can sign out, then sign in with a different account.
You can add another account, and use that.
A different account wouldn’t have access to the subscriptions and/or purchases of the former account.
You can change the name (email address) of an existing Apple ID account.
You can change the password of an existing Apple ID account.
These last two changes will keep the account properties intact, such as subscriptions and purchases.