I’m upgrading my Linux Mint 14 Nadia box to Linux Mint 15 Olivia, here is how i did
Change the repositories, replace all “precise” with “quantal” and “maya” with “nadia”
sudo sed -i 's/quantal/raring/' /etc/apt/sources.list sudo sed -i 's/nadia/olivia/' /etc/apt/sources.list
Update the system
sudo apt-get update && sudo apt-get dist-upgrade sudo apt-get upgrade
The installing process will ask you if you want new configuration files, you should choose “Y” to accept the new files. The old configuration files will be stored in the same directory as the new ones. If you are not happy with the new settings, you can restore back to your old configuration files.
Restart the system
sudo shutdown -r now