The bumper is secured under the black molding on your bumper. pull those 3 pieces of the bumper and you will see push in clips about 4 or 6 of them. once you have them removed you should be able to slide the front bumper forwards of the car.
Please use two persons to do this so the bumper falls on the ground when you slide it of. It is so much easier.
But before you do all this remember this . The front bumper had impact shocks who will shock in when you hit something. Bmw recommend them to replace them after impact. I normally pull them back out if the damage is not sever. if the damage is on the passenger side use your took and a cable to pull it back out so that you don't have to take the bumper of.
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