How do i solder LEDs to the x,o,triangle,and square buttons on a ps3 controller?

ive looked all over youtube and have found nothing, ive asked people with those mods on youtube but never reply. i put LEDs in ps3 and xbox 360 controllers for my friends (for money) and they all want to know if i can do that but i told them once i find a tutorial i can do it. can anybody recommend a video link or a website link or if you have time then possibly make a video and notify me at lilzach96@yahoo.com ? thanks