(Keep in mind that opening and running the. app/Contents/SharedSupport (This generates the app, and I will explain how the app is used) Move InstallESD.dmg to Payload/Install macOS. pkg file was unziped using pkgutil -expand-fullĢ. hdiutil convert /tmp/.dmg -format UDTO -o ~/Desktop/.cdrį1 - These ISOs were made using DMGs from this article.app/Contents/Resources/createinstallmedia -volume /Volumes/ -nointeraction hdiutil attach /tmp/.dmg -noverify -mountpoint /Volumes/.hdiutil create -o /tmp/ -size m -volname -layout SPUD -fs HFS+J.Download the installer: softwareupdate -fetch-full-installer -full-installer-version.