|So if you have any links that have been downgraded by PENGUIN they have already been disavowed by PENGUIN and you don't need to worry about them anymore. |
You can certainly delete, or edit with rel="nofollow" or disavow them - but what confirmation did you get that Google took action against "that particular link?" ... or will take action against that link in the future?
In my experience if such a link wasn't devalued by Google's PENGUIN all you are doing is destroying your ranks even more.