For World Creator 3, please follow the written below:
You cannot change the account holder email but you can change the assigned users including their email, name and password. Please login into your account, switch to License, and perform the necessary steps.
For World Creator 2, please follow the written below:
Please contact support@bitethebytes.com and send us the invoice or the email you have used to purchase World Creator. Please be aware that your request needs to be approved before changes can be made.