People listed as departmental heads (or faculty managers, or superusers) have the ability to view and edit departments, including the addition or removal of HoD permissions.
To change the heads of a department, navigate to the department homepage, and select the Overview tab (a). The current heads are listed in the first column (b), and to change these, click the Change HoDs button (c) to open the form.
Use the search field (d) to find the new person to add and select them using the checkboxes. The current HoDs are listed on the right (e), use the checkboxes (f) to add or remove people from the list. Be sure to click Save when you’re finished, and to return to the main page.