This method worked for me for upgrading the printer from USB stick
Based on https://forum.support.xerox.com/t5/Printing/Xerox-Versalink-B405-Fault-or-Error-116-313/td-p/214593
Download the firmware (.bin) file, refer to support page for the printer.
Create a folder named ‘DWLD’ on the USB memory device (FAT formatted).
Store the software download file (.bin) in the ‘DWLD’ folder
Switch off the machine, Insert the USB memory device (rear of the printer).
Simultaneously press then hold down the Home and Power buttons until the device powers on and SPECIAL BOOT MENU appears,
Simultaneously touch the letters A in SPECIAL, B in BOOT and the Home button. Do not hold any of the three locations, just touch/press then release simultaneously
At the keypad screen enter code number: 6789#. The SPECIAL BOOT MENU 1/3 screen will display.
Select Download Mode on SPECIAL BOOT MENU 1/3, then touch YES. The UI will display SW update progress. The machine will eventually reboot several times
You can find a video on Youtube for a similar printer that would show you the steps. Search for "Xerox C & B AltBoot"
