Posting Answer Here 3DS with sysNAND firmware v4.1-4.5 - If you have a 3ds that has a version before 4.1, find a retail cartridge with the 4.1 - 4.5 update on it ( http://www.eurasia.nu/wiki/index.php/3DS_Games_with_firmware_updates_in_the_4.1_-_4.5_range ) and do NOT connect to the internet when running the update from this cartridge. The 3ds is not downgradable YET, so take extra precaution. Gateway blue cart or similar DS slot-1 flashcart without PassMe - You should already have this. Download the needed files from here and extract everything. Navigate to "Blue Card (R4i)". Copy the files from it to the root of the microSD card you'll be using in the blue card. Insert microSD into R4i and put inside your 3DS. Run the R4i and select Gateway Installer. This will install the tools to use emuNAND. When it's done, press "Home". Take your 3DS' SD card and put it in your computer. Copy all of the files from it into a safe directory, and format it. Then, open the Gateway files and copy "Launcher.dat" to the root of the newly formatted card. Eject the card, and replace it in the 3DS. On your 3DS, go into System Settings. Go to Other Settings>Profile>Nintendo DS profile. This will boot the Gateway Launcher. BACK UP YOUR NAND BEFORE PROCEEDING. This is easily done in the Gateway Launcher. After you back up your nand, take out your 3DS' SD card and put it in your PC. Copy NAND.BIN and put it in a safe directory. Replace your SD card in the 3DS. Boot into the Gateway Launcher again and select the option to boot into Gateway mode. You are now running emuNAND and can use your Gateway.