how do i change my apple ID on my 3rd gen apple tv

Hey m12a34,

We see you'd like to change the Apple ID in use on your Apple TV.

You can do so under Settings > Accounts > iCloud. Click Sign Out to sign out of the current account, at which point you can sign into your desired one.

Take a look here for more info:

• Sign out of iCloud on your iPhone, iPad, iPod touch, Apple TV, or Mac

Cheers!