My cousin installed me the homebrew ike this:Ok then just copy arm9loaderhax.bin and boot.3dsx from this zip. https://github.com/AuroraWright/Luma3DS/releases/download/v6.6/Luma3DSv6.6.7z Boom you have luma and no data lost
Also if your concerned about breaking your 3ds then you shouldn't be hacking it in the first place.
Installing Ninjhax
Downgrading with Cubic Ninja
Installed MenuHax with Pasta CFW,FBI
I have homebrew launcher with boot3dsx and arm9loader from previous attempt to install Luma