The final Step of this guide is to install arm9loaderhax and setup Luma3DS to run just milliseconds into the boot. This is accomplished by using SafeA9LHInstaller by [AuroraWright](https://github.com/AuroraWright/).
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This will install [AuroraWright's Fork](https://github.com/AuroraWright/arm9loaderhax) of arm9loaderhax.
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We will also setup the ability to launch payloads from arm9loaderhax, giving us the ability to unbrick our SysNAND from situations that would normally brick us by restoring from backup.
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**You cannot use another console's OTP or you will brick GUARANTEED.**
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#### Overview of steps
In this section, we will go through the process that all the other steps have led up to: actually installing arm9loaderhax.
This is nearly the best possible kind of device exploit because it is permanently installable into the NAND firm partitions, and runs before most of the OS loads, allowing it to not only work on *all* versions once installed, but also protect itself and recover from most situations that would brick a non-A9LH 3DS such as a nonfunctional home menu or bad title install.
The file `arm9loaderhax.bin` is what is launched by arm9loaderhax itself after it finishes loading off of NAND, and can be any valid arm9 payload. This file can be replaced at any time, although Luma3DS allows for the launch of other arm9 payloads by holding buttons on boot.
In this case, we use Luma3DS by [AuroraWright](https://github.com/AuroraWright/) to boot a patched SysNAND directly, allowing us to completely bypass the need for any kind of EmuNAND, vastly simplifying the usage of a hacked 3DS in addition to saving SD card space.
Once arm9loaderhax is installed and Luma3DS is setup with the correct options, we then restore our previous backup.
**If you think your SD card may be corrupted, check your SD card for errors using [H2testw (Windows)](h2testw-(windows)), [F3 (Linux)](f3-(linux)), or [F3X (Mac)](f3x-(mac))!**
1.**If it exists, copy the `/files9/` folder on your SD card to a safe location on your computer and back it up to multiple locations (such as online file storage); the files inside could save you from total data loss if you break your system**
2. Create a folder named `cias` on the root of your SD card if it does not already exist
4.**Delete the `a9lh` folder from the root of your SD card if it exists**
+ **If you accidentally install arm9loaderhax using another device's `OTP.bin`, you will BRICK!**
3. Delete the `3ds` folder from the root of your SD card if it exists
4.**Copy _the contents of_ the `starter.zip` to the root of your SD card**
+ This will include a brand new `3ds` folder to replace the one you just deleted
15. Copy `Hourglass9.bin` from the Hourglass9 `.zip` to the `/luma/payloads/` folder on your SD card and rename `Hourglass9.bin` to `start_Hourglass9.bin`
16. Copy `aeskeydb.bin` to the `/files9/` folder on your SD card
17. Copy `DspDump.3dsx` to the `/3ds/` folder on your SD card
18. Copy _the contents of_`fbi-2.4.2-injectable.zip` to the `/files9/` folder on your SD card
##### Section II - Installing arm9loaderhax
1. Reinsert your SD card into your 3DS
2. Do the steps for installing arm9loaderhax on your device:
+ You should be on 2.1.0
+ Go to `http://dukesrg.github.io/2xrsa.html?arm11.bin` on your 3DS
+ If you get an error, [follow this troubleshooting guide](troubleshooting#ts_browser)
+ If you get a glitched screen, [follow this troubleshooting guide](troubleshooting#ts_safe_a9lh_screen)
+ Press (Select) to Full Install
+ The installer will now install arm9loaderhax on your device (this is very fast)
+ Shut down your console, hold the power button until it turns off if necessary
+ Copy your console specific `OTP.bin` from the `/a9lh/` folder on your SD card to a safe location on your computer and back it up to multiple locations (such as online file storage), then reinsert your SD card into your 3DS
##### Section III - Configuring Luma3DS
1. Hold select on boot to enter the Luma3DS menu
+ Make sure to start holding the button before pressing power
+ If you get a black screen, [follow this troubleshooting guide](troubleshooting#ts_sys_a9lh)
+ If you boot to SafeA9LHInstaller, [follow this troubleshooting guide](troubleshooting#ts_safe_a9lh)
2. Use the (A) button and the D-Pad to turn on the following:
If, before following this guide, you already had an EmuNAND setup and would like to move the contents of your previous EmuNAND to your new SysNAND CFW, now is the time to [follow Move EmuNAND](move-emunand) instead of doing the first four steps in this section.
1. Open Hourglass9 from arm9loaderhax by holding (Start) on boot
2. Go to "SysNAND Backup/Restore", then select the "Health&Safety Dump" option to dump Health & Safety to `hs.app`**(you can use Up and Down / Left and Right to change the name)**
3. Press (B), then select the "Health&Safety Inject" option
8. Select the FBI injectable `.app` for your region
4. Press (A) and confirm to inject
9. Press (Start) to reboot
10. If you still launch to the stock Health & Safety app and have downgraded with Gateway in the past, [follow this troubleshooting guide](troubleshooting#gw_fbi)
You can now use Luma3DS Updater to update your Luma3DS to the latest version just by opening it and pressing (A).
This is not the same thing as a System Update; it just downloads and extracts the newest Luma3DS files. Luma3DS Updater only updates the files located on the SD card.
This will only update the Luma3DS files on the SD Card. If you boot the device without an SD card, it will use whatever version you placed in CTR NAND.
To use [NTR CFW](https://github.com/44670/BootNTR/), get `ntr.bin` from the appropriate `.zip` on [this](https://github.com/44670/BootNTR/releases) page and copy it to the root of your SD card, then install `BootNTR.cia` from [this](https://github.com/astronautlevel2/BootNTR/releases/latest) page.
