: Insert the USB drive into the printer's front port. The printer should automatically prompt you to "Update" (even though it's a downgrade).

Before flashing, you must allow the printer to accept an older version: Need to downgrade firmware - HP Support Community - 8155346

: You need to find and download the specific firmware version you're aiming to downgrade to. This can be challenging since most manufacturers provide only the latest firmware versions on their websites. You might need to search through forums, support pages, or contact HP support directly.