electronic inquirey

for a while, the light was out for the temp. gauge in the instrument cluster. today, i just lost all lighting in the instrument cluster. everything else works fine and i checked the fuses that seemed to apply and they are fine.

any ideas of wtf

ps. since im gonna replace at least the one bulb anyway, let me now how hard it is to take that apart. i hear they are a pain in the rear in general but this one in particular doesnt look horrible to me but let me know if uve done it