Amazon is warning customers to update their old Kindle’s by today (Tuesday) or risk loosing their internet connection. That means you won’t be able to connect to the Kindle Store or sync with the cloud.
If your Kindle is plugged in (regardless of how old it is), it will have updated automatically. But if its not, open the menu and select “Sync and Check for Items.”
So what happens if you’re reading this article a month from now, and your Kindle is already offline? You’ll just have to do it manually by downloading the update file from Amazon’s website and transferring it to your Kindle via a USB cable. For more instructions, select your device on this help page.