Power up the Kindle Touch and connect it via USB cable to your PC. Drag the update file from your PC onto the Kindle drive (see below). (Make sure you don't drop the file into one of the folders within the Kindle drive, Amazon warns.)

Check the Kindle drive to make sure the upgrade file transferred successfully.

Eject the Kindle Touch and disconnect it from your PC.

To launch the software update on the Touch, tap Menu on the Home screen, then Settings. Tap Menu again and select "Upgrade Your Kindle." Tap OK when asked if you want to run the upgrade.

The upgrade will take a few minutes, and the Touch will restart twice during the process.