I agree, it's a very risky procedure.
I had a big flake of dust inside my 13" MacBook screen, that was driving me nuts. As it is an older model, and I have things set up so I can pop the same drive and boot my Hackintosh (as a backup), I thought I'd go for the surgery.
It's not for the faint hearted.
I disassembled things down to the "LCD Replacement" level, and got the LCD unit separated from the MacBook. (This alone isn't for the uninitiated.)
Examining it with a flashlight, the problem was indeed inside the LCD unit.
Feeling gutsy, I disassembled the LCD unit itself. Required careful removal of tape (including some metallic tape that no doubt served grounding purposes), and unhooking some catches around the edge of the metal bezel.
Then I was able to lift the LCD glass, and see two clear matte sheets whose job was to diffuse the backlight. Under the second one, I found and dispersed the big fleck of dust.
It took quite awhile, with bright lights in all directions, a HEPA air filter on high, and a lot of patience, to ensure I wasn't adding *more* dust inside the unit. In the blink of an eye (literally) an eyelash can land in there, making things worse than before. And you really should use those gloves that photographic folks use, to avoid adding any smudges inside the LCD. (I added a couple of smudges, and they were incredibly difficult to remove properly.)
Also, you want to ensure your work surface is clean, and has something soft on it. Removing dust is no good if you add some scratches to your screen.
Eventually I was satisfied that everything was clean and better than before, and reassembled. (A fairly long process, getting the LCD back together, re-running all the wires for the Mic, iSight, etc., around the sides properly, and getting the screen re-attached.)
Most intensive repair I've ever (successfully) undertaken. I'd only recommend it if you know what you're doing, have a relatively dust-free environment, and/or you're willing to potentially sacrifice your screen (and require a replacement).
It worked for me, and I'm very happy with the results. But I would never recommend anyone undertake this. :)
-DG