From what I understand, its friggin impossible. I think only a handful were imported to the US, and you'd end up paying somewhere well north of 10K if I had to guess.
I remember seeing somewhere an add-on for a Glock 17 that made it full auto, but it also involved lots of $$$ and lots of red tape. For turning an exceptional gun into a pretty useless bullet hose, its not worth it to me.
There is a device that will make any glock full auto. I know a class II manufacturer in Arizona that makes these for law enforcement. With that being said...