How can I remove the waves from my picture?

I have a 65" Samsung rear projection HDTV...it is a CRT based TV. The TV is 2 years old...about 6 months ago the picture quality was noticeably less crisp. There are subtle "waves" running through the picture...similar to the waves that used to be on those old analog TVs when it wasn't tuned exactly right.

Although these waves are annoying to me, they are not noticible by everyone unless they are pointed out. Of course, being an HDTV I would like the crisp picture so I'd like it fixed.

Is this something I can do myself? Perhaps the mirror needs to be cleaned?