1. There is to wire the FM antenna (original) and the DAB+ antenna, small module to stick on the windshield. Personally I didn't find it very good, so I stuck it on the rear window, the cable was just long enough, but I had to dismantle half of the car to pass the cable...
2. There is a micro explanation, you just have to stick the new antenna on the window, put a ground point (sticky tape) and pull the cable to the car radio. It's not very complicated, but if you don't feel like a handyman, it's better to let someone with experience do it!

To conclude, it's a good product, I'm completely satisfied, it works well :-)

1.- exactly, but of course there are all the connections to the electrical system (stand-by, start) and possible steering wheel controls or displays. The only problem with the installation is that the cable has to be routed between the windscreen and the steering wheel.
2 - The only problem with the installation is the passage of the cable between the windscreen where the antenna is attached and the bottom of the car radio. So if you're a maniac or not a bit of a handyman, it's better to let an expert do it. I'm not an expert, but I'm a bit of a broccoli, and I managed to do it, but a pro would be a pain in the ass...