- Switch off the phone
- With the phone switched off, hold down the “home” (house) and “back” (the arrow in the lower right corner) buttons
- Hit briefly the “end call” button while still holding the “home” and “back” buttons.
- Release the “home” and “back” button, a white screen containing technical information should appear, with a red message asking for hitting the “menu” button.
- Hit the “menu button”, the Hero will now boot with factory settings.
(originally posted by Oskyldig on a Google forum)