Here are the tools you'll need:
1 tiny Philips head screwdriver (#0, I believe)
1 sharp blade or a flat-ended plastic spudger
1 tray for all your screws and bits
OPTIONALLY, 1 set of tweezers
Step 1: Disassembly
1. Put the two switches on the left side on "Hold" and "Voice" (flick them both UP).
2. Pop off the battery part, exposing the USB jack.
3. Remove the 3 screws on the back of the main unit.
4. Open the two halves with a knife blade or spudger, starting from the top (where the mics are) and working your way down both sides.
5. Remove the 4 mic guards so you won't lose them.
6. Remove the top panel.
7. Remove the Hold/Mode switch panel on the left side.
8. Pop of the back panel.
9. Remove the 2 mics from their cradles at the top and the gold contacts from their cradle at the bottom (next to the USB jack).
10. Carefully tilt up the main PCB against the long edge (let it hinge along the side with the Play/Stop buttons).
11. Unscrew the 2 Philips screws to remove the button assembly.
I stopped at this point, but you could probably also detach the Play/Stop buttons on the right and REALLY take the whole thing apart. It all depends on the nature of what you're trying to do.