The unit will display a progress bar. DO NOT turn off the car or remove the USB drive during this process, as it can permanently damage the unit.
Start your car engine and keep it running during the entire process to prevent the battery from entering eco-mode. Turn on the Pioneer unit. dmhz5350bt firmware update link
This is the most reliable method for generic units. The unit will display a progress bar
You need a high-quality USB stick formatted to FAT32 . dmhz5350bt firmware update link