@RonaldB , the administrator that they are referring to are the Canvas employees that run the free for teacher Canvas instance, they are really the only ones aside from your student who are able to reset his password, and given that his account is locked, I don't see another option. The free for teacher instance isn't connected a specific school, so the only people that actually run that instance are employees of Canvas themselves.
That being said, here are a couple suggestions that I have for you:
1) Have your student create a new account with a different email.
2) Have your student sign in via a cloud provider (i.e. Google, Microsoft, Facebook, etc.). There are buttons he can click on the login page to seamlessly login and create a new account. This way, he won't need to memorize any username/emails or passwords to gain access to his account. He'd just click on the cloud provider's button each time he wants to login.
3) Reach out to Canvas support directly as the teacher. Ensure they know which course your student is trying to access, as well as their email associated with the account. This process however, can take a few days.
I hope this helps and clears things up a bit, reach out with any additional questions or concerns! Thanks!
- Noah