The power light is pretty simple. You just need to get the old LED out using a desoldering braid or whatever method you have, then just pop your LED in and solder it. There's also a resistor on the circuit board you can replace if you need to (depends on what kind of resistance your LED needs).
The controller ports weren't too bad either. I started by using my multimeter to find where the 5v's were. I Where the two red wires in the picture are connected to is the 5v. The white wire is to the ground. It's the same set up for behind each port.
(IMG:
http://img.photobucket.com/albums/v621/KiemRaekerm/Board1.jpg)
I couldn't get a good picture of it, but on the top of each controller port is a little metal slit that you can lit up and snip off with some wire cutters. I tested it and it's not really necessary, or at least as far as I can tell. Anyway, I then drilled a small hole about the size of my 3mm LED (I think it was 1/16 or something, eyeball it). I plugged my controller in the port and put the LED in the hole, seeing how far it could come down with the controller still being plugged in to avoid any problems with the controller hitting the LED. Then while holding the LED there, I put a little hot glue to keep it in place. Then I wired it up, shown in the picture above. There's plenty of room in the Gamecube, so I just fed the wires over the top of the board.
If you have any other questions, feel free to ask.
EDIT: Excuse my shitty wiring.
This post has been edited by KiemRaekerm: Dec 6 2005, 08:59 PM