HP generally discourages downgrading, but it is possible via the method.
Need the absolute latest file? Visit the HP Support Center and search "HP MFP 586 firmware" directly. hp mfp 586 firmware
Select the section from the list of available drivers. HP generally discourages downgrading, but it is possible
You can update the firmware using the printer's web interface or a USB drive. Method A: Embedded Web Server (EWS) Recommended for network-connected printers. HP generally discourages downgrading
Download the most recent firmware file, which typically ends in a extension.