Hello from Nawfick.
Well, discovered a trick to this although I'm sure there are others.
Yes, completely back out and remove the lower adjustment screw (not essential but helpful).
Two clip-shaped hold-downs remain at 3 and 9.
Push down the reflector at either side just below the clip end.
On the pushed-down side, insert the end of a flat-blade screwdriver between the reflector edge and the reflector cup, beside the clip.
Twist the screwdriver ever so slightly until the reflector edge clears the clip, and lift out.
Watch carefully for other pieces inside the reflector cup that want to escape and head for a dark corner on you workshop floor.
R,
Kevin