If you don't want a person to have access to your Vault anymore, you need to remove that user as a guest.
Removing guest access will not affect the license of that user. If you also want to remove their license, follow the steps in this article.
- go to myNomadesk.com
- Manage -> select the Vault that you want to remove the guest on
- go to Users & permissions -> select the user that you want to remove