The Ubuntu developers are moving quickly to bring you the absolute latest and greatest software the Open Source community has to offer.
Upgrading from Ubuntu 13.10
To upgrade from Ubuntu 13.10 on a desktop system:
Open Software Sources.
Press Alt+F2 and type in "update-manager" (without the quotes) into the command box.
Update Manager should open up and tell you: New distribution release ‘14.04' is available.
Click Upgrade and follow the on-screen instructions.
To upgrade from Ubuntu 13.10 on a server system:
Install the update-manager-core package if it is not already installed.
Launch the upgrade tool with the command sudo do-release-upgrade.
Follow the on-screen instructions.
Note that the server upgrade will use GNU screen and automatically re-attach in case of dropped connection problems.
Offline upgrade options via alternate CDs are no longer offered for Ubuntu Desktop and Ubuntu Server. Please ensure you have network connectivity to one of the official mirrors or to a locally accessible mirror and follow the instructions above.