Hi I have had the TV for about 8 years or so, and it has been very very good. It is now beginning to show its age, and has developed some slight discolourations in the picture, only a few. These are like smalish purple blotches which show up only on light couloured backgrounds like sky or such. A friend who knows more about these things tells me that it is very likely just dirt/dust on the optics/mirror on the inside of the set, and suggests that it would be easy for me to clean these myself. Question: would I be taking on a difficult task in attempting to open up and clean these items myself? Would I likely do more damage than good ny trying it myself? If it would be hard for me to do, would it be a costly thing to have a service place do it for me? The picture, ignoring these blotches, is still very very good so I would like to try and get it back to 'normal' if possible. Any one had this type of thing before?