That's very strange, as the Haynes Manual says there is a screw behind each temperature control knob that will provide for removal of the front face plate. My only idea is that perhaps your control panel has a quick-release button on the bottom of it, like my ECC panel does. You have to remove the radio, and then feel for a small square cutout, there is a locking button that you can press to release the unit. If that doesn't work, I'm stumped...