Remove the steel mast from the antenna base. Raise the car, remove the inner fender clips and escutcheon nut, then take out the antenna base. Check the grommet for damage and replace it if necessary. Slide in the new antenna with its lead, fix the escutcheon nut, and reattach the inner fender parts. Lower the vehicle, tighten mounting bolts, and secure the antenna mast. Seal the cowl attachment point with RTV, attach the new lead-in, reconnect the pigtail, and reassemble the grille and molding.