What is best way to dist-upgrade with a debmirror

[bagpussnz]

Hi,
I have a debmirror for feisty, gutsy and hardy (on a server called ubuntuupdate).
I have a number of users on feisty and I want to upgrade them to hardy. What is the best way to do the upgrade?

(apt-get dist-upgrade doesn't see any upgrade - do I just have to change feisty to hardy in the sources.list??)

My sources.list is....

# See http://help.ubuntu.com/community/UpgradeNotes for how to upgrade to
# newer versions of the distribution.

deb http://ubuntuupdate/feisty feisty main restricted
deb-src http://ubuntuupdate/feisty feisty main restricted

## Major bug fix updates produced after the final release of the
## distribution.
deb http://ubuntuupdate/feisty feisty-updates main restricted
deb-src http://ubuntuupdate/feisty feisty-updates main restricted

## N.B. software from this repository is ENTIRELY UNSUPPORTED by the Ubuntu
## team, and may not be under a free licence. Please satisfy yourself as to
## your rights to use the software. Also, please note that software in
## universe WILL NOT receive any review or updates from the Ubuntu security
## team.
deb http://ubuntuupdate/feisty feisty universe
deb-src http://ubuntuupdate/feisty feisty universe

## N.B. software from this repository is ENTIRELY UNSUPPORTED by the Ubuntu
## team, and may not be under a free licence. Please satisfy yourself as to
## your rights to use the software. Also, please note that software in
## multiverse WILL NOT receive any review or updates from the Ubuntu
## security team.
deb http://ubuntuupdate/feisty feisty multiverse
deb-src http://ubuntuupdate/feisty feisty multiverse

## Uncomment the following two lines to add software from the 'backports'
## repository.
## N.B. software from this repository may not have been tested as
## extensively as that contained in the main release, although it includes
## newer versions of some applications which may provide useful features.
## Also, please note that software in backports WILL NOT receive any review
## or updates from the Ubuntu security team.
# deb http://ubuntuupdate/feisty feisty-backports main restricted universe multiverse
# deb-src http://ubuntuupdate/feisty feisty-backports main restricted universe multiverse

deb http://ubuntuupdate/feisty feisty-security main restricted
deb-src http://ubuntuupdate/feisty feisty-security main restricted
deb http://ubuntuupdate/feisty feisty-security universe
deb-src http://ubuntuupdate/feisty feisty-security universe
deb http://ubuntuupdate/feisty feisty-security multiverse
deb-src http://ubuntuupdate/feisty feisty-security multiverse

Cheers,
Ian.