You need to remove the beak - there are 6 bolts holding it, two below the side panels.
I also had to loosen the oil cooler to get the TT guard to slide in and snap over the top of the cooler. There are two bolts holding the cooler on. I did it with the front end dissasembled since I fitted a TT HID lamp and fog lamp at the time as well. Should not take you too long and I'm sure you would only need to remove the beak (about 5 mins,) loosen the cooler (about 1 min), slide on the guard, tie it down and refit the beak and tighten the bolts.