You can change your All4 account from Channel4 official website. Follow the steps mentioned below:
Go to All4.com.
Log in to your account.
In the top navigation bar, click on ‘My 4’.
Then, click on ‘Account Settings.’
Go to Personal Details and click on ‘Edit Details.’ You can change your name, email address, gender, and address.
Once you made all the desired changes click on the ‘Save’ button.