So basically I'm confused on what to do. I was hacking a friend's n3DS with another n3DS which originally had A9LH but I upgraded it to B9S using https://3ds.guide/a9lh-to-b9s I bought SUDOKU on the source 3DS and followed https://3ds.guide/installing-boot9strap-(dsiware-game-injection) to the letter. Everything went fine until the after the system transfer. I put the source's SD card into the target and had the 3DS move the DSiWare titles (so now the source has no SD card). What I'm planning on doing is waiting a week after I finish hacking the target to system transfer back to the source and regain my NNID. My question is, on Section V of https://3ds.guide/installing-boot9strap-(dsiware-game-injection) what SD card should I use? The source's SD card (which is now on the target) or the target's original SD card? Also, I already have boot.firm on the source's SD from when I updated it from A9LH to B9S, is it safe to keep it? Lastly, where exactly is boot.nds?