I think the stock antenna cable could be re-used. It wouldn't be as efficient as a good RG-58 or RG-8X, but it is 50 ohms. I think you could use the factory antenna mount as well as long as you can find a CB antenna that will fit in the threads. That's going to be the hard part.
Although I think it can be done, I wouldn't recommend it. I think you'll be discouraged with the performance of the CB and get frustrated when you can't even talk to the guy right next to you. If you're going to go through the trouble of installing the radio, the last thing you want to do is impair the antenna system. You can hook the best radio in the world to a lousy antenna and it will perform poorly. In contrast, you can hook a modest radio into a great antenna and get stunning performance.
Just my $0.02.