Some antenna masts are attached to the side of the windshield pillar on the drivers side. Simply unscrew the two plastic holders and proceed with cable removal. there will be on some models a rear antenna incorporated in the rear windshield. this can only be replaced with the glass.
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.