How do I get rid of the unsupported packages mentioned during the upgrade from Lucid to Maverick?

If you want to remove unsupported packages then first list them using ubuntu-support-status --show-unsupported then use sudo apt remove <package-name or names>

You will then get rid of unsupported packages

In most cases you don't particularly have to remove those packages. That notice only means that those packages are no longer in Ubuntu's main component, and have been demoted to Universe (see this page for more information on components), which means that support for them is still available from the Ubuntu community.

If you still want to remove them, you can find out which packages they were by looking at the upgrade log (/var/log/dist-upgrade/main.log) in which you'll find a line that begins with "demoted:" containing a list of the packages demoted.

If you want to remove packages that are absolutely unused, sudo apt-get autoremove will do that.