I would remove the old one completely and shape a new one out of plastistruct (sheets of plastic). you can buy them at hobby stores in varying thickness. buy a pack with sheets the same thickness as the original "antenna" draw on the shape you want, cut out the basic shape with scissors then fine tune it with needle files, dremel bits and sand paper. prime and paint before attaching
attaching should be pretty straight forward, try securing a pin the the new antenna first by either putting a small hole in it or attaching it with aves
good luck!