Only Admins and Account Owners can Revoke Access
Only users with Admin access or Account Owners on an Organization can revoke user access.
Access can be altered and/or revoked to an Organization and all of its sites from the Users page.
Click on the revoke "X" icon on the right-hand side to remove access.
How to remove yourself from an Organization?
At this time, it is not possible to remove yourself from an Organization.
Please contact someone with Admin access on the Organization you no longer wish to have access to so they can revoke access for you.