On a Hitachi 2.5" disk, is there a way to remove an unknown ATA user password? I have access to MHDD, atapwd, etc, but there's not much I can do without actually knowing the password. Erasing the disk is fine, I don't need its contents.
Use the master password to unlock (or erase) the drive.
Note that hard drives often ship with factory-set master passwords; you may find one by searching the Internet for your drive model number.
If you're unable to obtain either the user password or the master password, you will be unable to use the drive at all.