@Bouakham-and-Henri0 that is such a shame! How unfortunate to have a guest want to leave you a good review, but accidentally leave a bad rating.
AirBnB consistently says there is no way to change reviews once they are posted. I have not heard of anyone asking about what to do in the case of obvious error. To have any chance of a fix, though, you will need to contact AirBnB directly. (This place is not AirBnB, but just a discussion board for hosts and guests.)
Even spelling mistakes in the names of hosts will not be corrected, @Bouakham-and-Henri0. Don't count on Airbnb reps' mood too much. It's a shame, but in a way has to be understood. Some mistakes cost dearly.
If the guest really wants to attempt to amend his review, he should be the one to contact airbnb about it. Airbnb is more responsive to guests than to hosts, and they won't listen to a host asking about a guest amending a review, for sure.