no bulb,they are led, check the connections going to the clocks before you try to get into them.
if you take the clocks out of the housing you can manipulate the plastic housing and get the rim/top off. i cant be more specific its about 12 years since i did it and the outcome was not a good one.
when i was testing it i touched the wrong terminal with a 12v feed and a diode on the printed circuit evaporated leaving just a black sooty mark
replaced the speedo in the end