Homebrewing requires you to use an AceKard which is able to run unsigned applications and custom made applications in your device. The steps required for you to use a custom application are as follows:
- Download the firmware from acekard.com and copy akmenu4.nds and _ak2 folder to the root of the microSD.
- Copy the NDS file into the microSD card
- Insert the microSD in AceKard slot and then plug-in the card to your device.
- Start Acekard 2i from the DSi menu to load the application launcher.
- Select your application and that's it.