Some time ago I added a simple message widget to our login page which notes to users that they can use either their email address or display name to login. With the upcoming changes that will prevent users from logging in with their display name I want to remove this widget, but for the life of me I can't find where to do so. Obviously on most pages when logged in as admin I can hit the little flyout button on the left to adjust these widgets, but I can't visit the login page while already logged in to do so!
It was many years ago I added this in the first place (and many versions ago) so I don't remember at all how I added it initially, doesn't look like a manual modification to the theme(s) or anything.
Note I am aware of the following plugin, but we are not using it and have never had it installed