Using Linux Mint 15, I noticed that I was not notified when a newer version of Linux Mint was published. v15 was treating me well but I like to run the latest. A clean install is always an option but I did not want to go through having to reinstall programs and backuping up my files. I found a great post on the blog below that describes how simple terminal commands can be used to upgrade the software. Simply, you are pointing your apt to the newer repositories and doing and update then upgrade.

To expand upon the original author’s methods:

• Make a backup of your files. This should work but you never know. This should go without saying.
• Make sure your sudo apt-get update is working properly. If it is failing before you do your update, remove your broken package references. It will avoid future headaches.
• This is going to take a while. Be ready to let it download and update all your existing packages. It will probably take you 1-2 hours.
• Monitor it because it will prompt you for input. I always entered ‘Y’ at the prompts.
• When I ran sudo apt-get upgrade, it gave me 0’s for all the fields. But on restart, Linux Mint 16 was there.

Sources:

• http://www.tecmint.com/upgrade-linux-mint-15-olivia-to-linux-mint-16-petra/
• http://www.linuxmint.com/