Just call them and do it before they change the law! I do believe that all you will need to do, is download the form on their website, fill it in, do the eye test at any opticians, they stamp your form as long as eye sight it good enough to drive, you take it to the Office des Vehicules. There they will take your old license, send you on your way, and a few days later a shiny new Swiss one will arrive... with a bill to follow!