Hazing on Tachometer for 996

I recently wiped down my guages with a damp cloth. The next day I have hazing and splotching showing from the inside of the guage. I'd like to clean this off, but don't know how to get at the tach guage. Any suggestions other than taking the car into the dealer and facing a $400 charge? The car is a 2000 carrera coupe. Thanks