USB vender ID about UNO

I have used Arduino Duemilanove as a component of our products.
Our product is a kind of sensor. It is used to connect with Windows PC via USB.
We purchased our vender ID from USB IF.
I used to rewrite our vender ID and product ID in Duemilanove using FTDI’s freeware tool, Mprog .

By the way, anyone ,could you tell me what I should do, when I use UNO ?
How can I rewrite our vender ID in UNO?
Can we sell our product not to rewrite our vender ID in UNO?
We don't make any clone board. We only embed Arduino board inside our products.
We buy Arduino board from Sparkfun or other distributors.

The UNO design replaces the FTDI chip with an atmega8u2. The USB Vendor ID, Manufacturer and Product strings are all part of the firmware loaded on the that. If you want to change them you'll need to modify them in the Arduino-usbserial Descriptors.c file and rebuild the firmware, then flash the new Arduino-usbserial.hex file to the atmega8u2 using DFU mode. You can find a guide to building the firmware on OS X on my blog here: Arduino Hacking. Building the firmware on Linux is similar.

Thank you for your answer.

I want to rewrite VID and PID for USB in Arduino UNO. I reset the 8u2. UNO became in DFU mode. I selected the device driver on Atmel\Flip 3.4.2\usb.
When I watch Device Manager in Windows7, I find the device driver, "AT90USB82" in tree.
But, there is "!" mark and I find error code52 on the device driver's property.
I try to connect Flip 3.4.2 with UNO via USB. But I can not. So, I can't rewrite hex file in the 8u2.

What should I do?