You will need another person to help you on this one. There will be a screw-type collar right on top of the fender, the upper most collar, not the lower one that attaches the antenna assembly to the fender. Take a correct size wrench and unscrew this counter clockwise. While some one sits inside the car and turns the radio on, have your helper pull up with slight force on the antenna mast. The mast and nylon tail, (this is the bottom portion of the antenna mast that engages inside the assembly, and makes the metal portion of the mast move) will come out as a complete piece, If pieces have broken off inside, they have will have to be removed, take the antenna motor cover off and remove the broken tail pieces, replace the cover. Now to install new antenna mast, you basically perform the same operations in reverse order. Sit inside car and turn radio off. Have your helper at the same time, feed the nylon tail into the assembly while turning the tail back and forth. This is to enable the nylon tail to engage into the gear underneath. When the antenna tail engages and the motor completes its cycle and shuts off, screw down the mast collar, (clockwise direction). After this is done, turn the radio off and on a few times, (allowing the antenna motor to completely cycle each time). This will properly time the antenna mast to the motor.