git clone https://github.com/chris1111/macOS-Package-HP-Prodesk-600-G1.git && cd macOS-Package-HP-Prodesk-600-G1 && cd OpenCorePackageProdesk && ./Build-Package
By installing this package it will install a specific EFI folder for the HP Prodesk 600 G1, so if you already have Open Core install make a backup of your EFI before using this program.