In order to hard reset a Amazon Kindle Paperwhite 3, you should perform the following steps.
Remember! Hard reset will delete all the data on your device; pictures, contacts, messages, apps and more.
Amazon Kindle Paperwhite 3 device will be brought back to the default configuration of a brand new device.
1. Power up the tablet by pressing the Power button.
2. Go to Settings > Reset Device > Yes.
3. Yay, done.