Hello @SarahY622 (Honora),
Based on your wording, it sounds like you're actually referring to the account owner no longer working at the organization? In that case, you'll need to login using the owner's credentials (including their MFA) and make the applicable changes in the account. If you're unable to login to the owner's user profile, you'll need to call our general support so they can securely collect details, and submit an ownership transfer case to their team lead. This process can take up to 4-5 business days, depending on case queues and the ease of which the team lead can confirm details with the involved parties.
If you are actually referring to one of your account's manager-type users no longer being a part of the company, the account owner can login and disable the manager's access to the account.
Taking over an existing account as a new user
Community & Social Media Support