You can only delete a user who is in invited state or has not accepted the user invitation yet. However, you can disable active users to restrict his/her access. In order to disable the user, you can follow the below steps-

1. Log in to your Orangescrum account with your admin credentials.
2. Click on the Users section in the left menu.
3. Find the user whose access you want to delete and click on the three-dotted icon on the top left of the user details.
4. Click on 3 dot icon on the card of the specific user and click Disable (Refer Image 1)
5. Click ‘OK’ .