To accomplish this, we can use the Download Play functionality of the game Mario Kart 7, using a 3DS with custom firmware already installed along with a custom game plugin.
This custom plugin will send a hacked payload to an unhacked console, which then exploits the system in order to inject the exploited WiFi profile into your connections list.
Once the WiFi profile has been injected, we will use SAFE_MODE, which is a recovery feature present on all 3DS consoles, to activate the exploited WiFi profile.
For a more technical explanation, see the following links for information on the kartdlphax and unSAFE_MODE exploits: [kartdlphax](https://github.com/PabloMK7/kartdlphax), [unSAFE_MODE](https://github.com/zoogie/unSAFE_MODE/).
* The latest release of [SafeB9SInstaller](https://github.com/d0k3/SafeB9SInstaller/releases/download/v0.0.7/SafeB9SInstaller-20170605-122940.zip) (direct download)
#### Section I - Hardware Button Check (target 3DS)
{% include_relative include/safemodecheck.txt %}
If the camera does not open, you cannot follow this method. If this is the case, join [Nintendo Homebrew on Discord](https://discord.gg/MWxPgEp) and ask, in English, for help.
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**:
In this section, you will copy the files needed to trigger the unSAFE_MODE exploit onto your target 3DS (the 3DS that you are trying to modify)'s SD card.
In this section, you will use Download Play to transfer the exploit data from the source 3DS to the target 3DS, which can be used to overwrite your Wi-Fi slots with hacked data. Your Wi-Fi connection settings will be temporarily overwritten while the exploit is active.
- If the screen freezes, hold the power button for fifteen seconds to force power off your console, then try again
- If you have launched kartdlphax previously, the last selected settings will be loaded. If they are correct, select `Use settings` and skip the next 3 steps. If they are incorrect, select `Change settings` and proceed.
- If the source 3DS freezes at this point and you are using a cartridge, try [installing the cartridge to the system](dumping-titles-and-game-cartridges#installing-a-game-cartridge-directly-to-the-system)
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. If the injection was successful, the screen will turn green and the **target 3DS** will automatically power off
+ If the screen turns red, power off the target 3DS and start again from the beginning of `Section III - kartdlphax`. If this doesn't work, ask for help at [Nintendo Homebrew on Discord](https://discord.gg/MWxPgEp))
You will **not** need to use your **source 3DS** to complete any further steps on this guide. Any further steps should only be completed on the **target 3DS**.
In this section, you will enter Safe Mode (a feature available on all 3DS family consoles) and navigate to a menu where unSAFE_MODE will be triggered, which will launch you into the boot9strap (custom firmware) installer.
1. With your console still powered off, hold the following buttons: (Left Shoulder) + (Right Shoulder) + (D-Pad Up) + (A), and while holding these buttons together, power on your console
+ Keep holding the buttons until the console boots into Safe Mode (a "system update" menu)
1. Press "OK" to accept the update
+ There is no update. This is part of the exploit
1. Press "I accept" to accept the terms and conditions
1. The update will eventually fail, with the error code `003-1099`. This is intended behaviour
1. When asked "Would you like to configure Internet settings?", select "Yes"
1. On the following menu, navigate to `Connection 1` -> `Change Settings` -> `Next Page (right arrow)` -> `Proxy Settings` -> `Detailed Setup` ([image](/images/screenshots/usm/safemode_highlighted.png))
1. If the exploit was successful, your console will have booted into SafeB9SInstaller
+ If your console instead freezes on a white screen, hold the POWER button until it turns off, then retry this section
+ If your console instead freezes on a red screen, you are missing `usm.bin` from the root of your SD card
+ If you get a different error, [follow this troubleshooting guide](troubleshooting#installing-boot9strap-usm)
In this section, you will enter the Homebrew Launcher (using custom firmware) so that you can restore the Wi-Fi connection slots that were overwritten in Section I.
