IF I READ YOUR POST WRONG I AM SORRY

if this helps great...i have the manual european type hvac control...much like your description it has three dials...1)driver heat 2) blower speed 3) pass heat

to remove this panel...

pull off the knobs on the sliders for air stream control

pull straight off the knobs that control those three dials

there you will find three nuts that are holding that panel on...DO NOT BE SURPRISED IF THE BLACK PLASTIC "CUPS" ARE DAMAGED OR CRACKED....that seems normal...

pull of the hvac panel

hope this helps

Jake