I think that these instrument clusters use LED's for lighting up the warning icons and lights. The dash is easy enough to get. Just be carefull not to break any tabs etc.
When I worked for Chevy, whenever there was a dash issue, we took them out and sent them in for repair or parts had exchanges on the shelf.
my 2000 F-350 superduty 7.3 has simple twist out push in new bulb and twist back in to the cluster. simple to change you can get a bulb about anywhere. took me about ten minutes to change mine. got the bulb from auto parts store. but even wal-mart has them. but don't they have about everything?
I got in my truck today, and the icon at the bottom left of the cluster, which looked like a airbag/seatbelt symbol flickered on and off for a couple of minutes. I shut the truck off and restarted it, and that light stayed off. Any ideas? The airbag light at the right of the dash was on during self test, by the way.