Unsubscribe an anonymous blog subscription

I have a customer who is anonymously subscribed to a blog.  She does not want to get the emails any longer but I do not know where/how she can get unsubscribed.

It does not appear that an unsubscribe link exists in the email she is getting.

It does not appear there is anything in the UI to do this.

I do have the GUIDs from the database for the anonymous subscription records

I am on 6.1.16

Thanks in advance.