Mine is a 1994, and it was a pain in the neck, but I was able to get to it as I have been in that part of the trunk before to replace my antennae mast for the radio (it had broken off inside the assembly which required its removal in order to pull all of the old mast out)
Take everything out of your trunk - all the carpets, even the spare tire -- here is why -- you are going to drop a piece along the way and it is going to go under the tire -- so save yourself some time and remove it first.
You have to remove the trim around the bottom rim of the trunk. There should be two plastic push pins that hold this trim in at the top on either side, once those are out, use a putty knife or five-way tool to pop the rest of the trip up - it needs to come up first as there are clips that slide down to hold it in place at the top.
Once that is out of the way, you next need to remove the trim panel on the left side of the trunk -- there are likely four self-tapping screws inside the little tool compartment that hold this panel to the frame -- remove those (be carefull, they can strip and/or snap off (one of mine is now stripped, and another is snapped off -- recommend using a ratched rather than phillips screwdriver. After you get those four screws out, there are a few plastic push pins on the bottom of this trim panel and there is also one at the top near the forward part of this panel.
Once that is all loosened up, you can pull it back and the piece that is on the rear of the trunk that folds under it (and is over the rear part of the trunk on that side) will pull back as well -- the rear piece of trim is actually glued to the rear - so don't try to pull it off, if you just kind of get both pieces out of the way, you will have room to do the work.
On the left side under the trim panel there is a curved piece of aluminum that looks like an upside down "U" -- there are two screws on the bottom of this U near the rear of the trunk -- those two screws are holding in the light fixture on the side -- they are short, but they do in fact go into the assembly. Before you remove them, put a cloth down on the surface underneath this area as there are holes that go out of your car on this surface - one goes into the bumper and the other is a drain for the antennae -- so, to save some time, put a cloth over this area for when you drop a screw so you don't lose it.
There is a wire in the way as you remove these two screws, but you should be okay to work around it.
Once you have these two screws out - you can put your putty knife or five-way scrapper tool behind the light assembly from the rear of the car -- there is a plastic piece on the top of the light that can be removed - there is a nut on the inside of the trunk that is holding this piece in place, but you likely don't need to remove it and can wedge your flat blade behind the light and "pop" it out -- there are two plastic "nail" devices that push into holders on the rear of the car -- the assembly should slide right out at this point.
Once out -- you can see where the lights are and can pull them out -- I went ahead and replaced both bulbs that do the light and brake function as well as the turn signal light that is in this assembly -- as I figured I had the thing out and the bulbs are cheaper than my time -- once you get the lights in - do yourself a favor and test them to make sure they work before you put it all back together.
To put it back together - push the back of the light into the rear and line up the holes on the side with the holes inside the frame on the left side -- wait to pop the rear back in until you get screws back in place - an extra set of hands is handy at this point as you are trying to line up the holds etc. Also, there were rubber gaskets around the assembly where the screws went into it - one stuck to the car, the other to the assembly - it is easier to get back on if you pull them off the car and mash them onto the light assembly.
A magnetic tip helps putting the screws back in -- remember the part about the cloth --
Once the screws are in, reseat the rear part plastic pins and put the rear trim back in place --
I hope this helps -- I spent a good deal of time trying to figure out how to get this thing off - and couldn't believe there were two screws deep inside the trim holding it in place --- The only reason I didn't break it off is that I found a photo of the back of the assembly and saw there were two screws -- so I went looking for them on the inside of the car frame on that side -- when I got them out, I thought that they couldn't be for the light since they were so short, but the assembly molds right to the frame at that point--so they were in fact the answer.