I'm not 100% sure they are LED'*, contrary to what lots of people think. They are in fact soldered to the circuitboard, so it can be a pain to replace them. There was a post some time ago stating that the problems are often not the bulbs, but rather broken solder connections that can be fixed by heating the board up with a hairdryer.
I think he may be right. I tore my IC apart trying to replace one bulb, gave up, and when I put it back in the car two more bulbs were out.