I don't know how I can get to the part where I can get to the part thats inside the top of the button in there.
I tried screwing the black washer, but that does not take it off. Isn't there someway to make the white thing safely come off?
This thread talks about DDR pad lighting but it's the same thing for pop'n. You need a ~12V power supply to light up the bulbs and two diodes to keep the 12V from the power supply and the 3V from the playstation circuit from interfering with each other. None of those drawn schematics are real winners (you need only two diodes, not four) but maybe you can figure it out.