To upgrade from Ubuntu 9.10 on a desktop system
1. Press Alt+F2 and type in “update-manager -d” (without the quotes) into the command box.
2. Update Manager should open up and tell you:
New distribution release ‘10.04’ is available.
3. Click Upgrade and follow the on-screen instructions.
To upgrade from Ubuntu 9.10 on a server system
1. Install the update-manager-core package if it is not already installed;
3. Launch the upgrade tool with the command
$ sudo do-release-upgrade -d
and follow the on-screen instructions.