You can change the username and email address of a user in Microsoft 365 admin center, but not the MOERA address.Convert the user to a cloud-only account to change the MOERA address.Procedure is not officially supported by MicrosoftTo ensure the user keeps Outlook and Teams license, assign a directly licenseMove user to a non-sync OU in Active DirectoryRestore the user from the recycle bin on the Azure Portal to set new password.Change email address in Exchange admin center and MOERA address.Change the username in Microsoft 365 admin center.Change the attributes in Active Directory to match the user's cloud account.Sync user back to Active Directory, then back to the syncing OU to restore sync and processing.