first, get Padus DiscJuggler (demo version) from http://www.padus.com

then, download my VMU Backup CD in "Padus DiscJuggler Selfboot .CDI" format.... you'll download a .RAR file, you have to decompress the file with WinRAR and you'll get a .CDI file. Use DiscJuggler to "burn CD image" and select the .CDI file.

then use the disc on your dreamcast, that's all.