The iPhone uses the iTunes account information that is currently started on the device. To remove or remove an iTunes account from an iPhone, go to “Store” in the “Settings” panel. Choose to close the session to successfully remove the account from the phone. If you want to sign in to an account other than iTunes, touch “Sign in” and then enter the username and password of the account to add a new iTunes Store account on the iPhone.
Touch the “Settings” icon in the iPhone’s main menu.
Touch the “Store” tab under “Settings.”
Touch “Disconnect” to exit the iTunes account and remove it from your iPhone.