If your antenna mast is the type where you can unscrew the mast from the fender, simply do so with a pair of pliers. Most damaged antennas are simply the result of a car wash or similar mishap, in which the mast is bent.
Disconnect the antenna cable at the radio by pulling it straight out of the set. Depending on access, this may require loosening the radio and pulling it out of the dash. Working under the instrument panel, disengage the cable from its retainers.
On some models, it may be necessary to remove the instrument panel pad to get at the cable.
Outside, unsnap the cap from the antenna base. Remove the screw(s) and lift off the antenna base, pulling the cable with it, carefully. When reinstalling, make certain the antenna mount area is clean and free of rust and dirt. The antenna must make a proper ground contact through its base to work properly. Install the screws and route the cable into the interior. Make certain the cable is retained in the clips, etc. Attach the cable to the radio; reinstall the radio if it was removed.Power
Some models are equipped with a power antenna located in the trunk. Disconnect the negative battery cable first before working on any electrical components. To access the antenna, simply remove the trim panel from the interior of the vehicle. Detach the electrical wiring harness from the component. Unbolt the unit. The antenna may have a mounting nut retaining it to the outside of the quarter panel. Remove this nut and retainer to slip the unit out from inside the car. Pull the unit out from the vehicle.
Installation is the reverse to install. Connect the negative battery cable and check component operation.