quite right saying you want a new one put on, but its a hell of a big job.....
basically talking the skin needs taking off from the flloor round the wheel arch, up the tailgate across to the drivers door and back down to the floor again, all the welds will need to be ground off which is a job in itself to be done without damaging anything else. then a new skin will have to be welded on and sprayed. the roof panel and inside the tailgate will probably also have to be painted again as they will get discoloured from the weld.
really big job!