Take it to Apple, there are no parts available other than the fans and antennas at the moment. I believe the touch bar is also paired to an IC on the logic board due to the touch ID (similar to iPhones), so if the touch bar is swapped either the fingerprint scanner will not work or possibly the whole touch bar. At this point, no one is sure since there are no parts available to try this.
EDIT: My fault, was half asleep when I read this and assumed you meant touch bar ;)
As @danj says, it will need the whole assembly replaced if you take it to Apple. Alternatively, once the screens cover glass becomes available, this can just be heated, removed and replaced. Exactly the same way it can be done on the 12" Retina, so it might be worth living with it at the moment (12$ part vs $400+)