Deactivate a User
If you want to prevent a user from accessing the Server there are 2 options to do so.
Curators (Server admins) can deactivate users. Deactivated users can't access the Server. To deactivate a user go to the User Management page in the Server Admin interface. Select the user and uncheck the Active setting in the Permissions section.
You can also change the user's role to No Access in the General section of the user's profile.
You can't delete a Server user's account.