Källa: http://wiiforumet.se/m3i-zero-nyborjarguide-vt7014.html

Ladda in firmwaren på ditt M3i Zero

1. Tanka ner firmwaren från http://down.gbalpha.com/GBalpha/Softwares/F_CORE.zip
2. Packa upp och lägg in filen F_CORE.DAT på ditt microSD direkt i rooten
3. Sätt in minneskortet i M3i Zero kortet och stoppa in usbsladden som hängde med kortet, och sätt sedan in sladden in i datorn. Det ska då börja blinka en diod på baksidan av kortet. Gör det inte det, så testa att vända på sladden. Om dioden lyser med ett fast sken, så betyder det att den inte hittar “F_CORE.DAT” och det kan bero på att antingen så är inte minnet ordentligt insatt i kortet eller så ligger inte filen direkt i rooten.
4. När dioden slutat blinka, så är flashningen av firmwaren klar.. Detta kan testas genom att sätta in kortet (med eller utan minnet i) i ditt DS och se ifall det hittar kortet.

Sätta in menyn på kortet

1. Tanka ner http://down.gbalpha.com/GBalpha/Softwares/G6&M3DS-R_M67.zip
2. Packa upp och sätt mappen “system” direkt i rooten på ditt microSD. Om du fortfarande har F_CORE.DAT på kortet, så kan du ta bort den filen nu.
3. Sätt in minneskortet i ditt M3i Zero och stoppa in det i DS för kontroll. Nu ska du få upp menyn när du startar ditt DS. (på DSi så måste man själv klicka på spelkassetten, eftersom den inte autostartar)

Sätta in spel

1. Skapa en mapp som heter NDS direkt i rooten på ditt microSD.
2. Sätt in alla spel du vill ha i NDS mappen.

Fuska! (rekommenderas inte :))

1. När du valt vilket spel du vill spela, så tryck först “A” för att komma in i spelmenyn innan du kör igång spelet.
2. Tryck styrkorset en gång åt höger för att komma åt fuskmenyn.
3. Markera eller avmarkera vilka fuska som ska användas med “A”. Det går att bläddra snabbare genom fusklistan med Left och Right skulderknapp.
4. När du är nöjd (vissa fusk kan få spelet att krascha om de används fel) så tryck vänster på styrkrysset. Välj alternativet Cheat “allways on” för att det alltid ska vara aktiverat.

Hoppas denna guide är till nån nytta. :)

Source: http://alucard1990.hubpages.com/hub/How-to-unlock-the-most-out-of-your-Nintendo-DS-Lite

Okay, in order to make all of this a reality, you're going to have to acquire just a few things:

• Assuming you already have a DS, you're going to need a flashcard for booting homebrew, I recommend the M3i Zero, it's hands-down the best flashcard available. There are some other flash cards available, such as the R4, AceKard, Supercard DSTwo, and G6. These are also cheap and work in a similar fashion. My guide focuses on the M3i Zero, but all flash cards are designed to do the same thing, have fun!
• You'll need a micro SDHC card, I recommend that you purchase one of the ones listed below due to their high performance and low cost. These are the ones I personally use and they work perfectly for all my homebrew and media needs on my DSi.
• You'll need a micro SDHC card reader. If you purchase one of the micro SDHC cards below, it will come with one, so don't even worry about this.
• Obviously, you're going to need a computer to download files and transfer files to the micro SDHC card.

• You'll need to download the latest m3i zero firmware.
• You're going to need to download the F_CORE.DAT, but only if you have a DSi or DSi XL. If so, go to the system settings and see which firmware you have, if it is 1.4U, then download this, if it is 1.6U, then download this. If neither of these are working for you, then refer to this page —→ HERE, and on the right make sure it is the LATEST VERSION, and you should be fine. There have been a lot of issues lately with the F_CORE's I provide here, so this should take care of that. =D
• Extract the contents of the m3i zero firmware to the root of your micro sdhc card. If you don't have an extraction tool, download 7zip, its free and easy to use. After you install it, just right click the rar file you downloaded and click extract with 7zip.
• Also extract the F_CORE.rar and Place “F_CORE.DAT” on the root of your micro SDHC card, just like you did with the “SYSTEM” folder.
• Make sure you have the “system” folder and “F_CORE.DAT” on the root of your micro sdhc card and insert that into the slot on your m3i
• There was a USB cable that came in the m3i package. You'll need to plug the thin strip end of that into your m3i. Use the picture to the right as a reference, it has to be done exactly like that. Plug the USB end of the cable into your computer. A light in your m3i will start to blink. When it is done blinking, unplug everything, your m3i is ready to use. If your m3i did not blink when it was plugged into the computer, you did something wrong, format your micro SDHC card and repeat steps 1-6
• Insert the m3i into your DS and turn it on!
• Upon booting your m3i for the first time, you'll be presented with two options in the form of rectangles: click “m3 sakura” on the left. There will be some options to configure, including the language specification. These should be self explanatory. You may now hide the “SYSTEM” folder and the F_CORE.DAT, so that you don't have to see them when you add files to your m3i or when you are using it.
• You can also the change the appearance of your m3i, or the GUI (graphical user interface) by clicking on the “system” folder and then clicking on the “m3sakura” folder. There will be a few files in this folder with the extension “.skn”. Clicking on one of these .skn files will change the theme of your m3i. You can also download more skins online.

If the only reason you got into this whole thing was to be able to play music on your DS, congrats! You're done. Simply drag and drop mp3 files from your computer to any location on your micro SDHC card and your DS will play them, because it has a built in media player. There are homebrew programs available that will play music, but with the m3i zero you simply don't need them.

As far as watching movies on your DS goes, click here for my hub on this topic

You can drag and drop nintendo DS roms to your microsd card and play them on your DS. These backups run just like the real thing. However, you are only supposed to have backups if you own the real game. Using a backup copy of a game you don't actually own is illegal and you could get in serious trouble. That being said, here are some good sites to get some NDS roms from:

Romulation
Rom Freaks
And hey, there's always torrents, haha!

Always make sure you are downloading the USA (NTSC) version of your roms. Always make sure you are downloading the USA (NTSC) version of your roms. Other regions will work as well, but they'll either be in Japanese or they won't work as well. Although I've used European (PAL) versions of roms and they haven't given me any trouble yet.