How do you replace the antenna mast on a 1994 Lincoln?

A new mast from the dealer is about $50.00. You would remove the nuts and grommet at the base of the mast. Then press the up switch, or turn the radio on to get the nylon gear to despool itself from the car- it is best to have two people do this- so one knows which direction the gear teeth face. Start the new nylon gear into the shaft and then turn the radio off, or depress the down button to get the antenna to retract into the car. It may take a few tries to get it- just remember which way the gear teeth are facing before you remove the old one. Replace the hardware, and snug it down.