All you need to do is to run few commands to upgrade your existing Ubuntu to latest version.
Previously I have written few posts with every new release of Ubuntu. This time I was not willing to do the same. This procedure is identical, the only reason I cameup with this post is to add one more command.
Following commands will update Ubuntu from shell.
sudo apt-get install update-manager-core
With above do-release-upgrade command metadata is checked for regular & lts release. which is used to determine latest version & for upgrades.
There are many articles which explains easy way to upgrade ubuntu using GUI, this one is for shell lovers.