they may be the wire clips you are looking at....
take a few photos and draw a diagram showing the orientation when you take one out....
sure you will remember how to put them back in a week or two
or you may just post on here asking how they fit....
or do one at a time...
I use long nosed pliers to hold the clip and a screwdriver to lever one out as the first one does tend to "ping" around the room, just tricky to hold teh light and the clip and lever the clip with the screwdriver
you could try the alternative way as I did.. which was to smash a lens as you can hold the assembly very easily... then spend months finding a RHD one to match.... (not a good idea)
the clips are often rusty and loose their spring so you may need new ones...
Also look carefully the 3 bolt backing mount has a notch that corresponds with a raised lip on the headlamp to locate them when they are back in the car and don't turn in the mounting... some repro headlights don't have this lip...
I had a pair that didn't, I carefully worked out the correct position they should fit in the mount and filed a bit of metal on the rim and put a bit of solder there and filed that to correspond with the notch on the mount.
Ohh I believe a D should have alloy rims not chrome...