I have a Ubuntu 9.04 server which has no packase support anymore. If I want to update my package lists, I get th following errors:

 Err http://de.archive.ubuntu.com jaunty-security/multiverse Packages
   404 Not Found [IP: 141.30.13.10 80]
 W: Failed to fetch http://de.archive.ubuntu.com/ubuntu/dists/jaunty/main/binary-amd64/Packages  404 Not Found [IP: 141.30.13.10 80]
 ....

I read at the official Ubuntu-Support-Page, that there is a update-manager-core-Package to upgrade to a new release. Unfortunately I dont have this package installed and I am unable to install it because of the lack of package sources.

EDIT: Installing the package update-manager-core from another release doesn't work because it depends on a higher version of python-apt. (Tried with 10.04)

 $ dpkg -i update-manager-core_0.134.7_amd64.deb
 Selecting previously deselected package update-manager-core.
 (Reading database ... 28743 files and directories currently installed.)
 Unpacking update-manager-core (from update-manager-core_0.134.7_amd64.deb) ...
 dpkg: dependency problems prevent configuration of update-manager-core:
  update-manager-core depends on python-apt (>= 0.7.13.4ubuntu3); however:
   Version of python-apt on system is 0.7.9~exp2ubuntu10.
  update-manager-core depends on python-gnupginterface; however:
   Package python-gnupginterface is not installed.
 dpkg: error processing update-manager-core (--install):
  dependency problems - leaving unconfigured
 Errors were encountered while processing:
  update-manager-core

So, whats the best way to upgrade to to current Release without reinstalling the complete (virtual) server?