CD player whine ... how big and costly a fix?

I have a four-year old AIWA JAX-S5 stereo (3-cd changer, 2 cassetes, radio, about a $150 unit). I have started getting a distinct whine with most every CD I try to play. It seems to be particularly bad with CDs that seem to be a bit lighter in weight than normal (which is a lot of them lately). It is particularly bad, to the point of causing read errors, on the first three or four tracks of a CD. On the later tracks, the whine doesn't appear.

I've done some homework online and it appears this is a resonance problem, and there is a particular problem with a particular Sony optical pickup. I'm not sure this is that unit, but being that Sony=AIWA at that point in time, and I'm getting the symptoms that have been common to that pickup, circumstantial evidence tells me it's likely to be that pickup.

I know there were Sony service updates put out about this problem detailing the fix of putting a brass washer on the pickup and a felt pad on the bottom of the top clamp assembly. That sounds simple enough to do, except that I'm rather unmechanical and don't have a clue what to do, which means taking it to a tech.

I'm not a cheapskate and am willing to pay a tech for good work ... a couple of years ago I spent WAY more than the thing was worth to get a tech to do repairs on my first CD player, a Magnavox boombox that was made in Germany

20 years ago, because it was worth it to me ... and I'm willing to spend a bit to get this fixed if it's not an arm and a leg. The thing is, though, I've disliked this stereo since I got it and unless it's going to be a cheap and quick fix, I'm almost inclined to ditch it and get something else. I'm also concerned about being able to get the Sony parts to fix this, since it seems like it's been a while since that service update was put out and this unit is relatively old.

So, what am I looking at here?

Thanks in advance for any help.