I've had this with mine. You can buy a bulb from Vauxhall for about 50p. However you are then better off buying a haynes manual and allowing 2 hours plus to do the job.
Disconnect the battery, remove steering wheel, air bag (be very careful and make sure battery is disconnected and left for 10 minutes) remove steering column covers, remove radio, remove dash from around radio to the drivers door. Then simple twist screws hold in the instrument panel.
Don't take the car to vauxhall overwise a 50p bulb will probably cost you near £100 to replace.
Paul
Paul Lockwood, January 2007