Upgrade from Ubuntu 12.04.1 LTS to 12.10
We recommend you backup your existing Ubuntu installation before updating.
If you have a version of Ubuntu other than Ubuntu 12.04.1 LTS, please read the upgrade notes for more information on how to upgrade.
Before you start the upgrade, we recommend that you read the release notes for Ubuntu 12.10, which which include workarounds for any problems you might encounter.
Launch the update manager
Press the Superkey (Windows key) to launch the Dash and search for Update Manager
Check for updates
Click the Check button to check for new updates. If there are any updates to install, use the Install Updates button to install them, press Check again after that first update is complete – then press the Upgrade button.
Install the upgrade
A message will appear informing you of the availability of the new release. Click Upgrade and follow the on-screen instructions.
And if you get stuck… Ask Ubuntu