I just had to do this, I bought the 84-96 Antenna and it does not work I had to buy a universal antenna with a swivel ball type mount on my XJ . You will need to remove the inner fender liner to install the new antenna. An you will have to remove the kick panel on the XJ to run the antenna through the stock location.

 

I just found out the same thing. I did discover I could fish the antenna in from the bottom up throught the hole. But the base is to small and goes right through the hole in the fender I have one more idea but will probably have to take your approach.

 

Exactly what got damaged ? If the antenna mast got broken, unscrew it from the fender mount, and screw in another one.

 

This could only happen to me. I have an antenna that is for AM-FM but is also for shortwave general coverage. It is a bit larger than a normal and has a spring loaded base as mentioned. This all mounted nicely to the factory base until a big chunk of ice/snow slid of the top and bent the base. No damage to the antenna but the base bent so badly it lost contact.