Just a notice:
After downgrading to 1.0.0 you most likely won't be able to connect WiFi. The WiFi credentials you've entered in 1.1.1 are saved in the system, but not available to 1.0.0 and you get an error message while trying to enter new credentials. So you need to sideload the 1.1.1 Firmware.
1. Download from B&N:
http://images.barnesandnoble.com/pre...avo_update.dat
3. Sideload the update by putting it on the root of your nook's internal sd card.
4. Eject your nooks drives (Eject means Eject from right-click menu in explorer, not "Save Removal" from the taskbar)