Sorry to jump into thread 3months after, did you manage to do this? When i had Corsa C i was thinking to change the whole instrument cluster. Theorerically, it should be easier than disassembling the one you have now. Plug the instrument cluster, plug the Opcom. Read the eeprom from new cluster to get the security code, then "virginize it", and simply enter the security code of your car. In theory.I'd like to replace my black dials with white (and get the rings if possible) and I might do that if I permanently take the Tour to Spain and change to a pure km/h dial. There's an ebay seller called Dials4U that makes replacement faces. I'd have to do red needles for a white dial, of course. I was thinking red nail varnish, maybe?