Here I will show you how you can make your B button on your wiimote light up on/either Rumble or all the time.
LED 3mm , color of you choice
Solder and 15watt soldering iron
Resistor (if you want)
Tir-wing screw driver
About an inch of wire
And thats about it
Heres what the final product will look like :)
Also you can get everything else form Radio Shack.
Here is my youtube video of it in action http://uk.youtube.com/watch?v=9M6cHJIr65k
Step 1: Lets Get That Wiimote Apart and the B Button Ready for the LED
First take apart your wiimote, then take out the B button. Bend your LED somewhat like this (see picture one) I put more of a curve on my led to get it to fit better, just play around with it until you get the feel right.
Then solder wire to the LED ends, make the wire about 1 1/2 inches long. Insert your LED into the B button. You can either remove the far bottom clip like i did or just put it by the clip.(what i did was once i removed the clip i took my solder iron and poked a hole threw the tube) picture #2 is where you remove the clip. NOTE: the positive (+) leg of the LED is the smaller piece of metal if you look into the clear part of the LED and the negative (-) is the other one.
Picture #3 is where you melt (optional) a hole threw the tube on the button. If you did this step, all you do is melt a hole about in the middle of the tube until you can fully insert your LED. Make sure not to melt the top of the tube because if you do it will be really hard to put the button back together and have it feel smooth.
Step 2: Putting the Case Back Together and Testing the Light.
Once you have your LED in your B button and your wire soldered on the LED put your PCB back on the bottom part of your wiimote (make sure you have your wire out to the right for the vibrating feature) Then you'll see the wire for the rumble and a small + and - on top of the PCB (look to picture one) and solder the wire form the LED to the PCB(I would test this out before final solder)
pop some batteries into the wiimote and turn on your wii and scroll over some icons to test the rumble.
If everything is working right put your wiimote back together and go to step 3 to have a party!
Step 3: PARTY TIME!
But wait, what if you didn't want it to light up on rumble you say? Never fear I have the perfect option for you. If you would like the button to stay lit all the time. Solder you wire to these 2 points in picture #2
Please let me know if you have an questions.
Hope you enjoy your new mod and remember I am not responsible if you mess up you wiimote. Have fun :D