Tbh, there isn't much more to add to the step to step guide.
To anyone who's having issues, here's what I did:
1) Copy the mset cia for your region to the INTERNAL microSD of your N3DS.
2) Get a spare microSD and format it.
3) Copy launcher.dat to the root of both the new microSD and the one you're using in your N3DS.
4) Copy
DevMenu.3ds to the GATEWAY microSD. Make sure it's DevMenu and not BigBlueMenu. If it says Title Manager it won't work!
5) Insert the new microSD into your N3DS internal card slot. (The one with nothing on it. just to be sure)
6) Boot your N3DS, wait for it to create the necessary files on your microSD, it will say creating home or whatever.
7) Start the gateway launcher by using Zelda or Cubic Ninja.
8) Select "Install NVRam" and let it finish.
9) Insert your Gateway into your N3DS,
boot Gateway mode.
10) Press select, choose "devmenu.3ds" (Bigbluemenu didn't work for me, might work for you, if you need a devmenu that worked for me;
http://download1709.mediafire.com/51mhqofkddyg/wd5u7w040bjeq97/4.5 CFW Files.rar )
11)When in devmenu, press the right arrow on your 3DS once, and it will take you to a new menu, where you can choose (mset."your region")
12. Press A, and it will start to install
13. shut down your 3DS, and remove the New SD we used for this process. It has served it's purpose and is no longer needed. Put in your Old 3DS SD with your EMUnand.
14. Start up your 3DS, you will be in sysnand. Go to system settings, and choose "Other settings > "Profile" > DS profile
15. If everything worked, you should be in EMUnand at this point!
Credits to DarkKaine of course for the original step by step guide.