There are 2 options available: 


Option 1:  Revoke Admin Access


Step 1:  Click on the 'Groups' icon.



Step 2: Hover your cursor to the right of the user you wish to demote and click on the three dot User menu.




Step 3:  From the dropdown, click 'Remove Admin Access.'




Option 2: Delete the user from your account 


Step 1:  From the dropdown, click 'Remove from Project.'