With the seal removed you can see that there are pretty large openings around the edge of the front element mount. It might not be clear from the pictures, but those three slits (the screwdriver is in one) go straight into the lens body. I assume that if that seal isn't completely tight these provide a pretty easy path for dust into the body. This probably also explains why the dust problem only seems to affect those who don't use a UV filter (I don't use them, I'm convinced they affect IQ, but that's another issue altogether.) The three small screws are Phillips size 000. You can remove them and it looks like they're all that's holding the front mount in. Yeah, I'm thinking about it. I did try a Rocket blower into the slots but it didn't budge any dust as you can tell.