Went through a car wash and it broke my antenna. Yet another thing BP has screwed up, I guess

So now I need to replace it. I want to replace it with a factory antenna. As opposed to some people I've read about on here, I like having my antenna just a bit higher than the cab. I go through a lot of parking garages and like the fact that the antenna hits overhead beams and signs before my cab will.

Anyway, I found several posts describing prying the plastic cap off at the base of the antenna and to be careful not to scrape the fender or break the cap. Once past taking the old one off, how hard is putting the new one on? Does anyone have any pictures of it? Or any helpful advice?

Where's the best place to get a factory replacement on the cheap?

Thanks for the help!