kartdlphax is an exploit for the Download Play mode of Mario Kart 7. It can be used with universal-otherapp to install custom firmware on target devices.
In order to follow these instructions, you will need the following:
- A second 3DS with custom firmware (the **source 3DS**) that is the same region as the 3DS you are trying to modify (the **target 3DS**)
- A physical or digital copy of Mario Kart 7 that is the same region as both consoles
- An SD card for both devices
### 必要なもの
On the **source 3DS** (the 3DS with custom firmware):
* The latest release of [kartdlphax](https://github.com/mariohackandglitch/kartdlphax/releases/latest)
* The latest release of [Luma3DS 3GX Loader Edition](https://github.com/Nanquitas/Luma3DS/releases/tag/v10.2.1)
On the **target 3DS** (the 3DS that you are trying to modify):
1. Copy kartdlphax's `plugin.3gx` to the following directory on the **source 3DS**'s SD card, depending on the **region of your copy of Mario Kart 7**:
- USA: `luma/plugins/0004000000030800`
- EUR: `luma/plugins/0004000000030700`
- JPN: `luma/plugins/0004000000030600`
- Create the `plugins` and `00040000...` folders if they do not already exist
1. Eject the SD card and put it in the **source 3DS**
#### Section II - Prep Work (target 3DS)
1. Insert the SD card of your **target 3DS** in your computer
1. Copy `boot.firm` and `boot.3dsx` from the standard Luma3DS `.zip` to the root of your SD card
1. Navigate to `Local Multiplayer` -> `Create Group`
1. Power on the **target 3DS**
- Ensure that wireless connectivity is enabled
1. On the **target 3DS**, open the Download Play application (![]({{ "/images/download-play-icon.png" | absolute_url }}){: height="24px" width="24px"}), then select "Nintendo 3DS"
1. Join the group created by the **source 3DS**
1. Select "Start" on the **source 3DS** once it has detected the **target 3DS**
1. Once multiplayer has loaded, navigate to `Grand Prix` -> `50cc` -> (any driver) -> `Mushroom Cup`
1. Wait a while (a percentage should be displayed on the **source 3DS**)
1. If the exploit was successful, the **target 3DS** will have booted into SafeB9SInstaller
#### Section IV - SafeB9SInstaller
1. Wait for all checks to complete
1. When prompted, input the key combo given on the top screen to install boot9strap