- Launch a Terminal
- Type in: sudo apt-get update
(this will ping all the upgrade mirrors to determine if they are live and what upgrade packages are available).
- Once completed – type in: sudo apt-get dist-upgrade (this will start pooling down the various packages to do a distribution upgrade. Keep in mind – apt-get update will just do an update within the same distribution).
Note: Ubuntu now has an Update Manager that is available by launching the Unity search function and typing in – Update Manager. This is a GUI method of upgrading. I have had failure with this method personally so recommend using the command line for distribution upgrades for more visibility.