Hope you can help! I have a standard K2 blog on one of my sites and one user posted a comment, he clicked on "Notify me when new comments are added". He would now like to be removed from this mailing list.

Is there anyway to remove a certain subscriber from being notified of new comments to an article?

Please could you assist.

Thanks!

Unfortunately notifications per user are not supported.
You can look at the JED or here - getk2.org/extend to search for a K2 extension which extends the core notfication functionality.