- Take a spare SD and format it with SDFormatter (on Windows)
- Put launcher.dat on it
- Make a new folder "CIA'
- Copy your clean cia files in there
- Place the SD into your 3DS
- Take your Gateway SD
- Place BBBMenu or Devmenu on it (you can aswell place PlayCoinSetter on it (optional))
- Place SD back in Gateway and Gateway in your 3DS
- Boot your 3DS and let it configure the SD
- Launch Gateway, this will boot you in Gateway SYSNAND
- How will you know that you are in Gateway SYSNAND? press "Select" and the multirom menu will show up in the top screen
- Choose PlayCoinSetter and set it to 300 coins (optional)
- Press "Select" and choose Devmenu or TitleMenu
- It will show up in your Gamecart icon, select it and boot it
- go to your CIA folder and select to install all cia's
- Wait for a long time

(depends on your clean cia files
- When done, power off your 3DS
- Boot your 3DS again
- Your clean CIA files will show up in your normal SYSNAND and you can play them.
- If you are on FW 4.5, you can't play MH4U, Zelda MM, Pokemon OR/AS/X/Y, those need higher FW
- If you are on FW 9.2, you can play ALL clean installed games
- You can't play online cause MH4U/Pokemon OR/AS/X/Y Zelda MM all need updates
- Don't use CIA's to update them, it will not work
- If you want to update all your clean games (those that need updates) There's another way to install your updates (rxTools) but you need to make an emunand first (Search GBATemp)
- If you decide to make an emunand on that SD, BACKUP your SD first (Copy EVERYTHING to your PC)
- Boot Gateway Menu and make emunand (this will format your SD)
- Turn off 3DS and put everything back on your SD you backupped before
- Boot 3DS and boot into GW Emunand
- Update Emunand to 9.5.0-23x with CIA files obtained from 3DSNUS if you want
- You can play every clean game now in Emunand and Sysnand

- Don't use CIA's to update them, it will not work
- If you want to update all your clean games (those that need updates) There's another way to install your updates (rxTools) (Search GBATemp)