[mengchengfeng]

I don't believe you need internet connection - IRRC jailbreaking steps were plug in the Kindle, drop the jailbreak folder into the root directory, then choose `Update` from the Settings screen.

The hardest part was finding the `Update` menu item. It's only visible if you go to Settings, then press the menu button again while on the Settings page.

Not sure if registering the Kindle was required.