Installation should take roughly about 20 minutes if you're familiar with soldering. Make sure you are in a low dust area, it will bite you in the ass if you're not careful. Here is a quick run down of what you need to do. First, get a hold of the previously mentioned tri-wing screwdriver or mini 1/16". I didn't have either, so what I did was, take a small flat headed screwdriver and filed the tip down. I wasn't about to go out and buy another screwdriver to add to my collection.
There are a total of 7 screws, 6 located on the outside and 1 located within the battery compartment. Take them all out and keep them safe.
Lift off the back casing and you should see the GBA mainboard. According to the manual, there should be 2 screws you need to remove to get this mainboard out of there. There are actually 3 in mine. If you need to know, I have the AGB-001 model. Once the screws are removed, lift the board up and over.
Now take the buttons out of the front casing for the time being. Remember which buttons go where. The gray fuzzy cushion covers the actually LCD screen. Included in the kit is a black plastic card which you can use to pry open the LCD. Its stuck tightly by a black adhesive layer, so pry harder if it doesn't come out. Be careful, I got some adhesive residue on my plastic screen by shoving too hard.
Next, you're going to have to remove a piece of plastic right under the plastic screen. This is next to where your start/select buttons should be. I just took my pliers to them and ripped them out, some people prefer the filing method. This is explained better in the manual with cooler pictures. I also had to chop some of the adhesive off at the bottom to leave room for the Afterburner unit.
At this point, you are supposed to take the AR film and apply it to your LCD. Problem is, when I applied mine to the screen, it bubbled like crazy and then I tried to reapply it and I some how dropped it on my carpet. Oh well, good thing they sell replacements on their site. But sure would have been nice if there were two films in the kit. So I left out the AR film, hopefully this won't cause the unit to go bezerk. Maybe I'll replace it later.
Now that's what the whole light device looks like. The plastic sheet doesn't light up, just the top and bottom. This is the time you're going to solder on your two wires, black to the left, red to the right at the bottom.
Look at the mainboard, you should see a row of soldered points. There is one labeled S2, attach one end of the resistor to that and leave the other end like so in the picture above.
Solder your red wire over to the other end of the resistor and the black wire to the ground point on the GBA. The ground point is the largest soldered area to the left of the resistor. Put back all the buttons and close your GBA, your done.
But wait! There's more! Included in the kit is a small potentiometer. You modders should know what these are, but for those who don't, it lets you regulate how much juice is flowing at any time by the turn of a dial. This will allow you to adjust the brightness of the light!
I hacked the pot into the top corner of the unit, which is recommend by the manual. To fully utilize this pot, just take the wire from the Afterburner unit and soldered it to the pin 2, and solder the other end coming from the resistor to the pin 1. I drilled the hole so the pot could fit, notice the scratch line in the back of the unit, I slip a little in my excitement.