This guide is for those who are upgrading from Ubuntu Edgy Eft 6.10 to Ubuntu Feisty Fawn 7.04. To do other upgrades the instructions are similar except for step #6 where the names are (obviously) different.

  1. Update Apt:
    sudo apt-get update
  2. Update packages:
    sudo apt-get dist-upgrade
  3. Restart to get the latest kernel etc:
    sudo reboot
  4. Back everything important up now! If you haven’t done so already. ;o)
  5. Backup your apt configuration:
    sudo cp /etc/apt/sources.list /etc/apt/sources.list.edgy
  6. Open your source list with your favourite editor, in my case nano:
    sudo nano /etc/apt/sources.list
  7. Comment out any references to install CDs at the top using a hash at the start of the line(s).
  8. Change every occurrence of the word ‘edgy’ to ‘feisty’.
  9. Save the file. In nano hit ctrl + x, then hit Y.
  10. Update Apt again:
    sudo apt-get update
  11. Upgrade to the new distro:
    sudo apt-get dist-upgrade
  12. Restart:
    sudo reboot

Finished!

This sequence worked perfectly for me. Milage may vary, so make sure you follow step 4 and backup everything. Hope this helps someone out.