Anyone with Super Admin or District Super Admin access can change the access level of a staff account or delete the account.
To do this, select Settings to see a list of all of the users at your school or district, broken down by current access level.
Click the JiJi icon to the left of a user's email address to edit their account. Select "Change Role" to set their new role using a drop down menu. If you select "No Access", they will be removed from ST Math.
See also: What are the different access levels for staff accounts?