Upgrade Ubuntu to newer release

From GUI:

a- Update the system before to upgrade:

Before to upgrade, we need to update the system, press C trl+Alt+T , and enter the following command:

 sudo apt-get update && sudo apt-get dist-upgrade

To upgrade, open terminal and enter the following command:

 sudo update-manager -d

Update Manager should open up and tell you: New distribution release ’13.04 ‘ is available ( See screenshot bellow).

upgrade-ubuntu13.04

Then click : Upgrade

upgrade-2A new screen will appear asking you if you want to start Upgrade:

upgrade-4

Press start upgrade.

Now don`t close your computer until the upgrade is finished.

upgrade5

- From CLI:

To upgrade from Ubuntu 12.10 on a server system to Ubuntu 13.04:

1- install the update-manager-core package if it is not already installed:

 **sudo apt-get install update-manager-core**

2- Edit /etc/update-manager/release-upgrades and set Prompt=normal ;

3- Launch the upgrade tool with the command

 **sudo do-release-upgrade -d**

and follow the on-screen instructions.

Important: This is a beta release. Do not install it on production machines. The final stable version will be released 26th of April 2013.

- See more at: http://www.unixmen.com/how-to-upgrade-from-ubuntu-1004-1010-1104-to-ubuntu-1110-oneiric-ocelot-desktop-a-server/#sthash.l3sYpXrm.dpuf