To change users' data, customer key user can use the Edit existing user form.
To edit a user, just enter correct data on the form and click the Create button.
Select:
a user from your company
user's activity: to activate or deactivate a user
user's rights: regular or key user
Enter the other fields as well. Some of them are not mandatory.
→ Then a ticket is created and immediately closed. You can use it as a history of changes made in your company users.
If you want to edit email address(es) for your user(s), please create a ticket on Customer Service Portal.