I saw a guy on YouTube explaining how to ship a one wheel. He was on the phone with FedEx (or maybe it was someone else) and they told him that he needs to put it in the original box and bring it to one of their shipping centers (not a branded service location or whatever) and that they would handle it.
I suggest also checking if it's possible to receive a OW in France (I'm guessing it should be fine), because I had to cancel my Pint because my country (Serbia) doesn't accept "dangerous goods" by air.