Note: You need to be an Administrator to delete user accounts!
Steps
Navigate to the Manage users page from the left menu.
Use the Search to find the user’s account by searching for their email address or name.
Once you have found the account you would like to delete, click on the Trash can to the right of their name.
Extra notes for Single Sign-On (SSO) users
If the user you want to delete was created as an SSO user there actually have two accounts you must manage:
Their corporate SSO account with your company's Identity Provider - this is the account used to validate their login credentials and grant access to third-party systems.
The account you created within this system that contains all their data and permissions.
If you delete/deactivate either of these accounts, it does not remove the other.
If you deactivate their corporate SSO account the user will no longer be able to login and access their device, however, their data is still held by the system. If you reactivate their corporate SSO account again, they can login again and continue where they left off.
To completely remove this user's data from the system you must also delete the account using the above steps.