I spent all morning doin this conversion. I had recently done the wiper switches and dash guage LED conversions, so to match the white LEDs elsewhere, I wanted these to be white too. I tried doing just the single LED in the blue bulb holder like explained in the first post, but because it gave it a green tint and was rather weak, I decided to do it alittle bit differently.
I angled the LEDs up toward the illuminated parts of the button and used seperate LEDs for each one. (i.e. 2 LEDs in the ON/OFF side and 3 LEDs on the other side)
I used hot glue to keep them in place and then soldered them all together. They seem to be pretty bright but its only daytime right now. Heres some pictures: