Remove the 2 screws at the top (you'll need a Torx screwdriver for this), then pull the grey handle off - slide it along its axis, by pulling away from where the screws were.
Then you need to remove the inner "cone" - just pull it to detach it from the main cyclone bit (the one with all the holes in it). This exposes 3 more screws. You can now pull apart the cyclone assembly.
There are 2 more screws inside the cyclone assembly if you want to disassemble the whole thing, but this shouldn't be necessary.
Jim, September 2006