Step 1: Get bus and device id

lsusb
...
Bus 001 Device 051: ID 16c0:05dc Van Ooijen Technische Informatica shared ID for use with libusb

this is the programmer

Step 2: wire the sucker up

(15- sck, 14-miso, 16-mosi)

Step 3: change usb device permissions cus we’re too lazy to fix the udev rule

sudo chmod 666 /dev/bus/usb/001/051

Step 4: AVR dude

avrdude -p m32u4 -c usbasp -P usb -U flash:w:Leonardo-prod-firmware-2012-04-26.hex