2 weeks update: I did with the new charger more than 600km and about 10 charging, with no issues.
Some more details and some advices if sombody is trying to do the swap:
No reprogramming or other software setting are need. I had LeafSpy in the case I need to delete some errors, but it wasn't necessary. After the swap, the 6KW option is automatically displayed.
The swap itself probably took 2 hours from the moment I've started to remove the screws of the charger.
The difficult parts are removing some of the screws which connect the charger with the rest of the motor, because of the small space around them, removing the screws of the electrical connection between the charger and motor(no direct visibility) and of course removing the top cover because it is glued. For the cover it was hard until I found a tool and a position to properly force it without damaging anything. Then, when it started to move a little bit, it was easy to insert a screwdriver in the gap.
Then I have some issues removing the rubber water pipes because of the metal elastic ring which keeps them tight and finding a cap for them.
Before removing the 12V battery, wait 5 minutes so the computers will stop. At least that says in the Service manual, otherwise it might generate some errors on computers. After you remove the 12V you can't open your trunk anymore, so take out everything you need.
I lost a lot of time with the screws around the windshield. A couple of them were hard to unscrew and screw them back. The space is tight and you have to take care to not break the glass.
Please don't touch any electrical components on the boards because an electrostatic discharge might destroy them. Also don't touch the contact area of high power connectors. They have to make a very good contact with each other for the high power they transfer. Before I've removed the screws for the power connectors, I tried to estimate the maximum force at they were screwed. I don't know how sensitive they are if too much screwing force is applied.
The puzzling part was removing the high voltage switch. It is plastic and I was afraid it will brake.
Also when manipulating the new charger, pay attention to not put the weight of it on the cooling water pipe. It is glued or something. Mine bent and loosened, so I had to glue it to have no leaks.
And of course this is my experience with the swap. There is a risk involved, so be prepared.