We have a 46" RCA. It was purchased in 1999, so it's a few years old. Our screen has a black spot on it - it looks like a squished bug behind the screen. There is also a drip mark from something being spilt on it. Can these screens be replaced? How easy/hard is it? Does it have to be done by a repairman? I've looked on the RCA website and they have no information on my model anymore. Any help would be appreciated.