Only Security Administrators can remove users. In the example below, we display the current list of users and then remove the user spate. We then re-run the command to confirm that the removal took place. Note that you need to specify the username.
$ hicli user listUsername Full Name Privileges---------------------------------------------------secroot Security Administrator SEC_ADMINspate Steve Pate CLOUD_ADMIN$ hicli user rm spate$ hicli user listUsername Full Name Privileges---------------------------------------------------secroot Security Administrator SEC_ADMINAll objects (Cloud VM Sets and VMs) are owned by administrative groups and not by the users themselves. Thus, if you remove a user, the object will stay intact.