You probably already know this, but the two end buttons that say "Electronic" and "Control" will not move at all. The four buttons in the middle should be able to be pushed in one at a time, while pushing a second one will cause the first to pop back up. If this doesn't happen with moderate pressure don't force it. These switch assemblies are not easily found, but they can be freed up with care. It may require removing the switch assembly and soaking it in penetrating oil or something similar. I have photos at home that show the switch assembly in detail that I can upload for you when I get back there so you can see it shouldn't be that hard to do, but whatever you do be careful when handling these guys. You don't want to have to look for another.