Nate:Near the bottom of the backing plates are small oblong plugs, probably rubber. If they are missing, there is an oblong hole about 1/4" high by about 3/4" long. When you pull the plugs out, you should be able go shine a light in and see a "star wheel". Turning this wheel adjusts the brakes. They make a "spoon" for adjusting them, but in your case a good sized flat screwdriver will probably work. Stick the blade in the slot to engage the notches of the star wheel, and pull down on the screwdriver blade to loosen the brakes. That adjusting screw if very possibly rusted and stuck, I'm sorry to say. If so maybe an overnight soak with a good penetrating oil will help.