part of the bumper is welded but if the rust is on the back of the bumper itself you can just replace the whole bumper its self. it is held on to the car with 4 bolts just next to the lights on the in side of them. they are 14mm bolts and once u remove those the bumper comes off with the air dam as well. also there are a few bolts under the air dam as well holding it to the fenders remove those as well.