There are a maybe a reason why you as the site admin would want to revoke access from an existing admin. Maybe, the person has left the organisation, the person has moved into a different role, or the person has breached your site's rule.
As a site admin you can at any time block or unblock a user on your site. This can be done by simply clicking on 'Block' in your People tab under Administrators.
Being blocked results in the user not being able to make access EHQ nor any of the projects that they had been granted access to. In addition, it will remove them from the mailing list of your EHQ site and they would no longer receive any newsletter you sent to your database from within EHQ.
It should be noted that only site admins can block other admins. In addition, users are not automatically notified about their status. If you wanted to let the user know that their access has been removed, you would need to contact them separately.
A red dot near the screen name of the user indicates that you have blocked that user. At any time you can click Unblock to unblock the user.
If you just want to change the permissions of the admin, for example, change a site admin to a hub or project admin, then click on the user name.
This will open the edit screen.
You will see the option to change the admin permissions to either just a Participant, or a Project Administrator or a Hub Administrator. Read our article on Access levels for EHQ administrator to learn more about what each admin can and cannot do. Once you have selected the level click on Update to save your changes.
Note - In EHQ you cannot delete users off completely. Read the article Can I permanently delete a participant ? to understand the reasons.