I have a user whose Zoom account is linked to a Google login. However, he no longer has that Google account. He needs to login just using a Zoom username/password. How can I unlink his Zoom account from Google, while not unlinking it from my company Zoom account?
If the email address for the account ends in @gmail.com, and the user no longer has access to this account, the easiest way is to add the user anew with the new email address, and transfer the licenses to that user in the process of deleting the gmail-based account. See this Zoom Support article for information about deleting accounts:
Important: Make sure the new user account is created on your organization's account first... that way the new user can be the recipient of the assets that belonged to their previous account.