2006What's a HU?

When the radio is on, the call letters of the station are hard to read because a light bulb seems to be burned out. How hard is it to change he bulb?Louis

How I disconnect the seat belt alarm? I/we wear our seat belts all the time, but I am a semi-retired carpenter and pile tools in the passenger seat. The alarm goes off, very annoying.Step-by-step please. Wood is my specialty not cars or computers.Thanx