1. Navigate to account.dat.com  to click on Workgroups to the left of your screen

2.  Scroll down to Workgroup Members to find the user you want to delete from the workgroup. To the right of their name you will see three dots (also known as a kebab). Click on the dots and hit Remove from Workgroup

3. Then click REMOVE

Note: Whenever there are changes made to the workgroup (adding/removing users or deleting/re-creating workgroups), it is important to have all the users within that workgroup sign out and login again to reflect the changes on their end.