Removing Atlassian Org Admin

  1. go to https://admin.atlassian.com/, locate your site name, and click on it.

2. Click "Settings" -> "Administrators" then click Remove the user (Org-Admin cannot remove itself).

 

Reference

https://confluence.atlassian.com/cloudkb/removing-a-site-admin-or-organization-admin-975031716.html