Multiple Leonardos as HID Joystick, how to change the names?

Hi,
i have 4 Arduino Leonardos as HID Joystick for my Retropie-Station...
is it possible to change the HID name of the Arduinos?

someone in the internet said by changing USBCore.cpp in hardware/arduino/cores/arduino/
(search for Unicode string 'L', 'e', 'o', 'n' ...) the HID name of the Leonardo can be changed,
but i can´t find the 'L', 'e', 'o', 'n' ... string in this file...

I just want to change the names to
Arduino Leonardo #1
Arduino Leonardo #2
Arduino Leonardo #3
Arduino Leonardo #4
...

flow86:
someone in the internet said by changing USBCore.cpp in hardware/arduino/cores/arduino/
(search for Unicode string 'L', 'e', 'o', 'n' ...) the HID name of the Leonardo can be changed,
but i can´t find the 'L', 'e', 'o', 'n' ... string in this file...

That someone had IDE 1.5.2 or older.
In newer versions you define build.usb_product in boards.txt.

You can add a product name submenu to the Tools menu by adding these lines to boards.txt

menu.usb_name=USB Product Name
leonardo.menu.usb_name.leonardo="Leonardo"
leonardo.menu.usb_name.leonardo.build.usb_product="Arduino Leonardo"
leonardo.menu.usb_name.leonardo_1="Leonardo #1"
leonardo.menu.usb_name.leonardo_1.build.usb_product="Arduino Leonardo #1"
leonardo.menu.usb_name.leonardo_2="Leonardo #2"
leonardo.menu.usb_name.leonardo_2.build.usb_product="Arduino Leonardo #2"
leonardo.menu.usb_name.leonardo_3="Leonardo #3"
leonardo.menu.usb_name.leonardo_3.build.usb_product="Arduino Leonardo #3"
leonardo.menu.usb_name.leonardo_4="Leonardo #4"
leonardo.menu.usb_name.leonardo_4.build.usb_product="Arduino Leonardo #4"

Thanks a lot!
worked perfect for me!