Ok this has been covered many times, but wanted to share my personal experience and result.
After failing inspection for nonfunctional 3rd brake light, I went straight to the forum for info and found that this light is a very common problem and at around $165 for new, there had to be some alternative. My spoiler light was also out and at $50 seemed to be the cheapest solution( spoilerlights.com). I did, however, want to see if I could fix the nonfunctional light.
Per another thread, I drill a access hole to the second hidden mounting screw and that worked very well. With a little flex of the plastic support, I had the light assembly out in no time. Total of about 10 minutes with drill, less 20 minutes trying to find a blasted small Phillips screwdriver.
I also saw a thread that showed how to break off 2 of the center leds and wrap a wire to get outer 2 leds working on both sides. Here is where the surprise came. I wanted to test the light before doing anything and ended up using 2 stripped wires and connecting the light to my computer power supply's molex connector. Initially I got nothing, but after wigglling everything around, it lit up! All the leds were functional and bright!
The moral of this story is, test the light, check your connections and with a little luck and a lot less expense, you could end up having a working light.
Makes me wonder how many people replaced or " fixed" a unit that just had some loose connections.