The upper section of the backing frame for the rubber bumpers, the “horns" need to be removed to clear the new grille. This can be done as neatly or as roughly as you can stand to look at. I prefer to have it look at least as good as Factory.
I used a hole saw to cut through the sides of the support, in front of the radiator mount. (Another method would be to cut the horn flush all the way back to the top frame filler, about 3” further behind the radiator bracket, where that notch is visible. There would be different cleanup were you to go that route.)