How to Upgrade Ubuntu 14.04 LTS to Ubuntu 16.04 LTS?
1.Update your system
First of all update the system with following command:
sudo apt-get update
Then upgrade the system
sudo apt-get upgrade
Then install the updates:
sudo apt-get install
2.Trigger the upgrade
Now you can trigger the upgrade with following command:
sudo update-manager -d
3.Wait for the update to complete
Now you should wait for the update to complete.
After restart you will have have latest Ubuntu 16.04 LTS
You can find all the steps in the tutorial video above.