Voilà ce que j'ai trouvé en bas de la page de téléchargement du thème. Je n'est pas eu le temps de tester!


How do I install an M3 theme? by darthdarovit

To install a BACKNDSS.NDS, first locate the BACKIMG folder that should be located in the root of your card: (Drive letter of TF Card)/BACKIMG

Place the BACKNDSS.NDS file inside the folder and your skin is installed.

To switch skins, navigate to the "Setup" button in the M3 Adapter menu and to open up the options. Find Background and hit your right arrow key to cycle through the different skin files.
If you rename your BACKNDS file it must be in either BACKNDSX.XXX or BACKNDS.XXX or else it won't be read by the M3.