Very nice detailed write up 👍I figured I would write up a little bit about this to help others on the way... for the most part this was pretty simple, I was just unaware of the over license plate light housing stuff to deal with.
I will do this in a few posts...
PART 1 - BUMPER REMOVAL
First ... Pre-LP Bumper Skeletons... known to get brittle/crack/lose tabs etc over time due to heat, and vibration etc... yay for plastic. For a long while it was thought you could only buy the inner plastic piece with the outer actual bumper but that is not true or at least no longer true. Glen at AMH Parts (no affiliation) has the inner parts at a decent price. You simply have to remove the old bumper, pry off the old inner frame from the inside and then replace it all.
There are a few videos online that show how to remove the bumper from the car which I would recommend watching. I'll just give an overview here of some of that as the bumper stuff is actually pretty straightforward...
1. Unscrew all the little screws holding on the rear hex panel bits. Chances are you already have lost some but all the smaller pieces have 4, one in each corner and the wider center pieces has 7 or 8. Try to make sure you keep all the screws or washers. You may want to order additional screws, washers and the metal bracket plates as well as for example my old bumper had lost several tabs... this meant that older backing clips, and screws etc were just "gone". So you will want replacements for the new one.
2. Remove the rear wheels. You hopefully know how to do this.... but generally loosen lug bolts on both sides before lifting the car. Then you can jack up from the rear center cross member and place jack stands at the rear jack points.... Remove the wheels because you have to remove the rear inner fender liners. These have to come off because A) part of is is screwed to bumper, B) bumper to upper quarter panel bolts are behind it and need to be removed and C) you will need access to pull out the side marker lights. All that to come...
3. After jacking up the car remove the rear fender lines. It's just all the outer screws. There are two silver ones on the inside that are machine screws. Most of the rest are typical other lambo screws. There is one on the upper diagonal inside that goes into the body work that is also different... Lastly there are two screws and washers on the BOTTOM you have to remove as well from underneath. After that the liner should very easily come out. I cleaned mine up. Be sure to keep all the screws organized and know what went where.
4. Disconnect all the lights. There are side marker lights that need to be pulled out of the housing gently... grab the rubber base not the wire and wiggle to remove. One on each side. Also there should be the main rear lights connector behind where you unscrewed all the original hex trim. Mine was on the right side but I have seen others in the center... It's an audi style clip so you use a screwdriver to manipulate the tab and pull the connector apart. My L shape tab wanted to come out so if it does be sure to store it somewhere safe for connecting later.
5. Unbolt the bumper. There is a bolt on each side on the upper inside corner where the fender line was removed - in front of the side marker lights. You will need a 10mm wrench on top and bottom to hold and loose from both sides. Put aside the washers, screw and bolt.
In addition to the corners there are 2 screws underneath the rear diffuser under the car - two on each side - that need to be undone.
Then there are all the screws in the bumper itself... the orange tabs on top that hold the lower bumper we are removing to the upper section. There is one on some of the corners to remove. Note you don't have to remove the double ones as that is not part of the bumper... look and you will see. Then the majority to remove are are on the bottom part of that middle trim area and sides. That's it. Bumper is technically loose but will probably hold in place since sandwiched on the sides with a mounting bracket and the side light housings.
6. Pull off the bumper. Best to have a friend tho I did it solo. I used some tape - arguably could have used some higher tack tape tho it worked. You basically pull out (carefully) from the upper side to slide off the side marker light cylinders from the inner frame, and then slide backwards the entire side/assembly. Be sure to have some blankets or towels etc to rest it all on.