You must go, in person, to a French Foreign Legion recruitment station. They're located in certain town across France. Getting yourself there is your responsibility, but once there if everything goes...
The headquarters of the FFL are in Aubagne,a town 10 kilometres outside marseille in france.IF this is a recruitment question go to http://www.legion-recrute.com/en/ or http://moremajorum.jigsy.com/...