Note: Backup important data and configuration files first.
First, apply latest updates to Ubuntu 8.x using:
sudo apt-get updateNext, install update-manager-core (if it is not already installed):
sudo apt-get upgrade
sudo apt-get install update-manager-coreFinally, start the upgrade:
sudo do-release-upgradeAnd just follow the on-screen instructions to complete the Ubuntu 9.10 upgrade.