Do not use this on a New 3DS, and even for Old 3DS, this should be a last resort. HzMod can cause crashes, create general system instability, and works at an average of 3 FPS.
Installing HzMod
What You Need
Your console's IP from the first section
The latest release of Snickerstream
HzMod
FBI installed on your console
Section I: Prep Work
Ensure that your console and your computer are on the same network
Download and extract the latest Snickerstream .zip file
Download and extract the HzMod .zip file
Take the SD card out of your console and put it into your computer
Copy the HorizonM.cia and HzLoad.cia files from where you extracted the HzMod .zip file to your SD card
You may put these files anywhere where you can easily access them
If you plan on streaming extended memory games, Copy the HzLoad_HIMEM.cia file to your SD card as well
Put your SD card back into your console
Section II: Installing CIAs
Power on your console if it is not already on
Open FBI
Press A on SD at the top of your bottom screen
Find the .cia files that you copied, press A on each one and select Install and delete CIA
Once you are done, press START to exit FBI
Section III: Streaming
Open the Snickerstream .exe file from where you extracted it
Change the Streaming app on the right side of the Snickerstream window to HzMod in the dropdown
On your console, open all the gifts that appeared on your HOME menu and open HorizonM Loader
If you plan on streaming extended memory games, open HorizonM HIMEM Loader instead
Your notification LED should now turn cyan, meaning it's ready for streaming
Input your console's IP from the first section into the IP box in the Snickerstream window
Click Connect! in the Snickerstream window
Your console's notification LED should turn green, and it's top screen should now be streamed to your computer
The low framerates are normal with this method and cannot be improved.
HzMod has now been installed and activated.