How to update firmware on Wyse Xenith with Wyse USB Firmware Tools? ANSWERED

Hi all!

I need to update firmware on a wyse xenith (C00X model) but I want to use Wyse USB Firmware Tools v1.16, because is more simple than DHCP option and share storage. (do not use ini file etc...)
I downloaded in support citrix website new firmware but they are .img extention.
In compressed file downloaded appear 2 folders :
C00X_2.0_015_EN (english version ???)
C00X_2.0_015_JP (japanese version ???)
and in each folder appear 4 files
bios.img, cmos.img, commandsXml.xml, par1.img
or USB Firmware Tools demand .rsp or .i2d file !
When I boot in usb key on Wyse, it see well usb key but "not operating system" appear.
how to push a new firmware in usb key to update Wyse xenith ?

And how to install hotfix (named C00_xen) on wyse xenith with usb key too ?

Many thanks !