Do all exactly whats told to do and call the script from an elevated cmd. The script mounts the install,wim you had to put in yourself and it does its work on it, and saves/unmounts it. Put the install.wim back in the iso, the install.wim came from, and the ei.cfg too, use iso to install.
This SKU is so obscure that even Wikipedia doesn't have any info about this. BTW, isn't Build 2004 the equivalent to insider editions due to 20h1 have not passed RTM yet?