I'm assuming you're speaking of the two really dusty screws deep inside the bottom of the cyclone, past the two main shafts.
There are actually four more really well-hidden screws on the same plate as those two.
A normal T-15 torx driver bit isn't long enough, because the hex-fitting of the bit can't fit in the recessed screw holes.
You need a hand-tool with a long, narrow shaft to be able to reach the deeply recessed screws at some obscure angle.
A small light really helps.
Locating the screws, they are next to the outer micro-dust holes, looking down into there, the bottom-right and upper-left.
The other two appear to be offset as upper-slightly right and lower-slightly left. They're along the same perimeter as the other two, but hidden beneath the main shaft walls.
I will see if I can reach them, but i hope this helps.
Sterling, January 2009