The easiest way to should be to use [HP PC HARDWARE DIAGNOSTICS 4-IN-1 USB KEY][hp-usb-key]. You should use this option if your BIOS/UEFI does not have a "BIOS update" option.
Unfortunately HP's automatic tool only runs on Windows, but it is possible to make a USB key formatted manually by running the self-extracting executable on Wine. You cannot simply extract the executable using 7-zip because the executable needs to do some file generation.