If you have been upgraded to rev530 or higher of Pro Cloud, you can manage your account users yourself using the Account Management Portal.
You can access the portal by going directly to https://my.designmanager.com/Account/Login or from within the software.
1. Click File --> Account Management Portal
2. Takes you to the Account Management Portal where you enter your Pro Cloud Username and Password
3. To add a user, click Add a User in the lower left hand corner. To disable a user, click the Disabled option next to the user from which you want to prevent Pro Cloud access.