To remove admin rights follow these steps:
• Click on 'users' on the top navigation bar
• You will see a list of all the users in your organisation
• Click 'Edit' on the kebab menu
• Scroll down to the Permission section and untick the checkbox that says 'Admin'
• Click the 'Save Changes' button.
You have now removed admin rights from that user and when they log back in they will be restricted.