Newer HP bioses can't be modded & flashed due to RSA signing. Only way to use official HP tools to change the OS SKU & thus turn on the hidden SLIC. Just disable Secure Boot from bios, create a dos bootable pendrive & put the tools in it. Boot from it & run 'nbdmifit' (w/o quotes). No chances of brick, as nothing is flashed. If OS SKU changing option isn't present, then you need to change the PCID.