This is a very outdated method involving an Action Replay with a Micro-SD slot on the side. This method should only be used if you do not have access to a hacked or homebrew 3DS, as it is not as reliable and requires an original DS, DS Lite, or DSi (This will not work with a 3DS or any variant, and it will not work with IR games such as Pokémon HeartGold, Soul Silver, Black, White, Black 2, or White 2.)
1. Make sure that your desired game and Micro-SD Card are inserted properly into your A