Now i'm trying to do this :
Reinsert your SD card into your 3DS, then get into the Homebrew Launcher through the entrypoint of your choice
I don't have any homebrew launcher installed in my 3ds, what can i do ? Do i have to use rxtools ?
edit :
I saw here : https://github.com/Plailect/Guide/wiki/Part-1-(Homebrew)
Because I'm 9.2.0-20 I have to do these step (except 3, 4, 5, 7) ?
Are you updated to 9.2? Just go back to part 1 and do that yes!