First I’m going to make a little disclaimer here.  The good folks who make linux mint don’t like rolling upgrades. They’d prefer you didn’t do this because it’s to be frank.. messy.  Doesn’t mean it’s not possible, and in the distrobutions that Linux Mint is built (Read Ubuntu and Debian) such a thing is certainly possible..

Even so. Backup your data.. and make sure you have a Distribution of your choice CD to recover from assuming it jacks up.  Oh and do not come crying to me.

ok so.. This tutorial assumes you have Sudo rights, or are running as root, and that you have an internet connection.

Step 1: You must replace your apt sources.  This means the /etc/apt/sources.list must be edited (or replaced) to contain at least the following lines:

deb http://packages.linuxmint.com/ julia main upstream import
deb http://packages.linuxmint.com/ julia-kde main upstream import
deb http://archive.ubuntu.com/ubuntu/ maverick main restricted universe multiverse
deb http://archive.ubuntu.com/ubuntu/ maverick-updates main restricted universe multiverse
deb http://security.ubuntu.com/ubuntu/ maverick-security main restricted universe multiverse
deb http://archive.canonical.com/ubuntu/ maverick partner
deb http://packages.medibuntu.org/ maverick free non-free

If you have any 3rd party sources in many cases changing the line.. “lucid” to “maverick” may be enough to connect you to the new repository. The same lines in the sources.list for the previous version of Mint (Lucid / Isadora) need to be either commented out.. or removed from the document. It would not hurt to backup your sources.list before you did this, but please move it to another folder.

Step #2
sudo apt-get update
to get your package list for apt.

Step #3
sudo apt-get upgrade
this will take a while.. I got an error at the very end with a mint desktop package, but I ignored it, everything else installed.
sudo apt-get dist-upgrade
this will update components that are held back by the above, but needed.
sudo apt-get -f install
this fixes some installs that might not have completed with the above.
*note.. it wouldn’t kill you to run these again.. Why? because sometimes they may depend on packages not installed on 10.04 to work.. either way.. I only had errors installing the “mint desktop” program on mine..

Step #4
sudo reboot
and cross your fingers. If it doesn’t work you can boot to a Mint CD or an Ubuntu one and copy your data off and reinstall. but if all went well.. you should boot up to Mint 10.

Step #5
sudo apt-get autoremove
Removes old packages no longer required. This removes old kernels now.
sudo apt-get clean
Removed the deb files cached for your installation.