Administrators can delete roles only if they are not assigned to any users. If you try to delete a role that is assigned to one or more users, an error message is shown and the role is not deleted. You can de-assign a role from a user in the User Editor, or in bulk via the User Data Loader (by exporting the users to a CSV file, updating their UserRole or UnassignRoles column, and then re-importing them).
You can determine which users are assigned the role you want to delete by creating a report in the Report Wizard. Select the User ID and Primary Role columns from User Properties, and the Role Code and Role Name from User Roles. Then filter the report on the Role Code or Role Name you want to delete. The report will list all of the users with that role, as either a primary or additional role.
To delete a system role
Additional Information