WoW Cata Alpha Guide.

First, download the Client downloader here: http://rapidshare.com/files/384203900/Cataclysm_Pre-Release_11927_enUS.rar
Beware, you need a funktioning enUS WoW install.
Then, install it!
TO start the sandbox, download this http://wowcore.ru/downloads/SandBox.exe.rar, launch it,
make sure that the sandbox.wtf file only contains 127.0.0.1,
change the realmlist of the Cata alpha version to 127.0.0.1, start cata,
username and password is admin and admin.