Launch the Software Updater
Press the Superkey (Windows key) to launch the Dash and search for Update Manager
Check for updates
Select the tab called "Updates". Then set the "Notify me of a new Ubuntu version" dropdown menu to "For any new version". Press Alt+F2 and type in "update-manager" (without the quotes) into the command box. The Update Manager should open up and tell you that a new distribution is available. Click Upgrade and follow the on-screen instructions.
Install the upgrade
A message will appear informing you of the availability of the new release. Click Upgrade and follow the on-screen instructions.