This is my step by step tutorial that I used to get the translation patch working. If anyone has any questions I will gladly answer them. Instead of decrypt9, I will be using 3ds Simple Cia Converter for the ncchinfo.bin and rxtools to get the xorpads.
This is for the o3ds and patching not NTR.
What you will need:
3ds Simple Cia Converter
RxTools
slot0x25KeyX.bin (Google it)
3ds 4.x-9.2
Fire Emblem If cartridge
Translation Patch
Step 1: First dump the rom of the game form the cartridge by either using Uncart or GW rom dumper.
Step 2: Put 3ds_simple_cia.exe into its own folder. Run it once and close it. There should be a bunch of folders that have appeared. Put your *.3ds into the roms folder and open up the program again, this time selecting "create 'ncchinfo.bin' file". A window should pop up and select the roms folder and save your ncchinfo.bin where you can find it.
Step 3: Plug in your 3ds sd card and drag the rxTools.dat, slot0x25KeyX.bin, and your ncchinfo.bin into the root of the sd card. From there, put it back into the 3ds.
Step 4: Open up your browser and click settings and delete/clear the cookies. Then put the url as launch.rxtools.net and you should automatically be put into rxtools. Scroll down to Decryption Options and then Generate Xorpads. This will take some time. At the end, if there is a messsage saying 'Could not open Sdinfo.bin' just ignore and return to the home screen and turn off. You now have your xorpads on your sd card.
Step 5: Extract the patch and patcher into a separate folder and in the same directory create another folder called "Xorpads". Drag all your xorpads into that folder and open the Patcher. Select your original 3ds rom, your Xorpads Folder, and the Patch Folder. Select Card 2 if you want it as a Card 2 Game and select Validate. This will take some time.
Step 6: After finishing validate, click Build 3ds or Build CIA and after some time you will be done. It should be called *_patched.3ds/cia
I hope this has helped some people. If there is anything unclear, ask and I will answer. I wrote this pretty fast so it might not makes sense in some places.