Dashboard fitting

Can someone please describe or take pics of or preferably both how the ends of an elf dashboard fits. It's the door side fitting I'm after as I can't get my head round it. Am I right in thinking that a bracket should be somehow fastened to the parcel shelf and then it screws via a bolt to that?

Mine were secured with wing nuts (4 No total.)
Each side section has one either end and these were accessable by opening the doors and reaching inside and unscrewing with fingers. The two side sections then just pulled away. The brackets to which they fix to are spot welded to the bulkhead. Mine do not have air vents so may be slightly different to those with air vents,I'm not sure. I should imagine the principle will be the same
Hope this helps.
Tony