Mine is also about 4 1/2 years but I use it in the bedroom so I don't think the hours on it are a lot. I did clean the mirrors on my old 62525 and it did make a big difference on the picture. I had step by step instructions to do it at the time. I haven't seen mirror cleaning instructions on the newer models so don't know how to do it on them? What are the hours on yours that you think you need to clean it?
19 HD DVD