Updating the Firmware on a Kindle 2021 (Easy step by step guide) - YouTube
How to Update Kindle Software Manually (Amazon Kindle eBook Reader) - YouTube
Another New Firmware Update for Kindles, Version 5.7.3 | The eBook Reader Blog
Amazon Releases a Firmware Update for the Kindle Paperwhite 3, and Other Models - The Digital Reader
2 kindle paperwhites same model in the same UK house updated to latest firmware now have different User Interfaces. One kindle won't activate new UI even after system reset and logging back