I don't think they are attached on the facia,
on mine I believe I took the stereo front plate off, just pop it off just clips around the edge
Then I believe there are two screws holding the heater control panel in place, from memory undo these, a few more clips and it came off leaving the guts behind
Mine is a standard heating layout, 3 knobs for heat, fan and air direction, and a few switches for air re-circ and heated rear window, mine is not the fancy computerised heating layout
didn't look to much at the switches and knobs so cant say how they were fixed
Good luck
Dave