The next part is tricky. The metal on these old units is very brittle. You need to CAREFULLY bend the tabs on the side of the face of the controller out just enough so that you can stick small screwdriver behind it to pop the face off. You only need to do one side, during reinstall you just slip in the side you didn't bend first, and them push the other side in, more on that later.
If you're not carefull you will break the tabs! Luckily I had two of these and I didn't break the second one!
