How to remove roof mount radio antenna fiat 500

Question edited for a lot more clarity.

This is a 1984 Fiat Tractor. With it being that old and a tractor, it would have been an option extra as it was in the old Fiat 500 cars.

https://www.google.com/search?q=fiat+12-80

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The two circular buttons have 4 removable plastic buttons around them if you take them off you have place for the special tool to remove radio

you can buy on ebay for 99p

INSTANT FIAT 500 RADIO CODE SERVICE BOSCH AND BLAUPUNKT MODELS ONLY 99p...

Ive done that a few times over the years when I forgot to push the antenna down when going through the car wash. Depending on where the antenna is, you have to get behind the panel it is mounted on. IE/ The guard, roof, windscreen frame. This will mean removal of whatever panel is behind to get to it.

The trick is to tie a cord to the old antenna before removing it. then pull the new antenna into place with the cord. All I can think of is to try and feed a length wire into the cavity till you can find the other end tie a cord to it and pull it through, then pull the new antenna cable into place with the cord.

the antenna is located in the roof and front fender have included a link to a schematic (basic location) , if not getting a good reception the best solution is to get an aftermarket fit antenna that mounts on the vehicle body because to try and replace this factory fitted antenna would be prohibitively costly
Antenna Amplifier in Electrical Lighting and Body Mobile Multi media...

remove the roof antenna ( unscrew off the mount) buy an aerial for the bumper. run the coaxial cable back to the radio and pull the existing cable out and after fitting a connector on to the end of the new cable plug it into the back of the radio. It will be a lot of trouble to remove the existing cable and roof mount and you will need it at a later date.

With the key off, remove the radio fuse from the fuse box, start the car (there should be no power to the radio if you got the right fuse pulled), turn turn the car off, then then put the fuse back in. That should reset it.
In my 2013 Fiat 500 it's the 3rd fuse up from the bottom, on the left side of the bus. 10amp, red fuse. (If you're unsure, use the web to look up a map of the fuses for your make\model\year. Don't justt start unplugging fuses... you may strand yourself.) -Good Luck!

Take the radio out and remove the coins is the first thing i would advise

You will need to contact a fiat dealer to get the code. They will require Vin number and proof of vehicle ownership.