This is a pretty easy one but very effective. heres what i started out with two of the light inserts for the ae92 sedan.

one is my old one because my brother backed into the side of my car messing up the tail light and a little of the side panel

heres what i did. i cut off one of the lights from the bottom because they will produce the most light and used the handy holes already in there to feed the wires.

on the reverse side i used this little wire clamp thing to wire the green and green/white coming from the end to the bundle of green wires.
and screwed the ground down also.

drilled hole for screw in backside

and here is it mounted and back in my car.

before:

after:

my camera is a pos that is why the light looks brighter. im thinking about doing it to the other side also and a glove box light but will probably put it on a switch.
design flaws:
-have to have the lights on the outside for it to work
-light is kind of in the way(can be solved with better placement)
-light blinds you if you look at it :P