Just rename Luma3DS's "arm9loaderhax.bin" into something that make you know it's Luma3DS (such as "luma3DS.bin"), then add luma3DS.bin to config file.
Then put CtrBootManager9's "arm9loaderhax.bin" to the root of SD/MicroSD. If you're using SDless build of A9LH, rename CtrBootManager9's "arm9loaderhax.bin"
to "arm9loaderhax_si.bin" instead. Whenever you boot your 3DS, it will take you to Boot selection menu.