1. I unscrewed and removed each bin, then sanded the entire surface with fine sand paper. After removing the sanding dust with tack cloth, I painted on a coat of primer. When that was dry, I painted three coats of the same black paint that I used to paint the drawer unit (in the first photo).
Tip #1 Disposable gloves will prevent the tack cloth’s sticky substance from getting on your hands. That stuff doesn’t come off.
Tip #2 Use paint that’s made for wood. It will give you a harder finish, but will take longer to dry. I used Benjamin Moore Metal & Wood Enamel in Space Black (2119-10).