What Do I Do if I Forgot My Kindle’s Password?
How to Reset a Kindle Device When You’ve Forgotten the Passcode
Turn on the Kindle so you prompted to enter the passcode. In the passcode field, enter: 111222777 Be patient. The Kindle will begin the reset process automatically and won’t requite any input from you until it’s time to set the device up again as if it was brand new and just out of the box
After everything is synced, you’ll have access to all the content on your Kindle, and the passcode will no longer be active.