Upgrade from 10.04 alpha 3 to beta 1?!

[jw12321]

Hi,
I installed the Ubuntu Lucid Alpha 3 a few days ago, but now I would like to upgrade to the new Beta 1. However, the Update Manager does not show any Ubuntu updates, and the server 'do-release-upgrade' says that there is not a new Ubuntu release available.

Is there any way to upgrade without downloading the ISO? Thank you.

[dabomb1022]

This has already been asked
http://ubuntuforums.org/showthread.php?t=1433805

[jw12321]

Thank you.