Always backup your current ROM before flashing. If the preloader is corrupted, you may need to use the Test Point method with SP Flash Tool to revive the unit.
Copy the patch files to a formatted USB drive, plug it into the head unit, and select Local Update in the system settings. android yt9216bj00012v001 patched
Most updates are performed via a USB drive through the device's or System Info menu. Always backup your current ROM before flashing