1. Ok first, get yourself the devmenu somewhere(Sorry, no links will be provided, Google is your friend). It should be named 3dsDevKit by BigBlueBox.. Also please upgrade your GW to 2.6 first.. 2. Extract the 3dsDevKit zip file(using WinRar/Winzip/7zip whateva) 3. RENAME the file DevMenu.csu to DevMenu.3ds(there should only be one inside) 4. Put this file in your MicroSD, just like how you put in any normal 3ds game. 5. ??? 6. Profit!! Enjoy This has been tested and confirmed to work, so please make sure you did everything correctly if it does not work.. FAQ: 1. How to install CIA files? Put it in your BIG SD card, launch devmenu, select import, and you are good to go. 2. I got errors while installing CIA. Seems like there are some CIA files(especially those released by BBB) will cause such error. Make your own CIA 3. Forced to restart Not getting this at all. Reinsert your SD card, make sure your SD card is inserted properly and firmly, then try again. 4. Can I install the devmenu_2x.cia? 5. When I launch DevMenu it shows Mario/some random game instead Try cutting everything from the MicroSD, then put back only the DevMenu, I suspect is caused by fragmentation error. If this method work, please cut everything out, then paste everything back in again.