Heater, radio removal ?

I'm trying to remove the radio, heater controls and the trim that surround them. Since the trim is 40 something years old I'm sure it is quite brittle. So I do not want to be prying on it too much so I do not break it. So my question is, how is all of this held in place on the dash? I need behind this stuff to replace the connector arm and bushing for the pass side wiper assembly.