jonjon95 There's an easier method for the n00bs.
Use arm7fixa which you can download from
here and is from this
thread
Create a directory and extract arm7fixa to this directory. Also place in this directory your [donor rom] and [your rom which needs patching]. Rename the [donor rom] to donor.nds. Click on [your rom which needs patching] and drag it onto arm7fixa.exe. That's it, it will create a file called [your rom which needs patching]-arm7fixed.nds. Next time you have another game to patch, you just have to place it in that same directory and again just drag it onto arm7fixa.exe, it's a lot faster than the older methods.
I used Summon Night - Twin Age (U)(XenoPhobia) as the donor, but there are plenty of others to use.
While Holding X and Holding A both work, X's old DMA mode definately runs the game faster than A's non DMA mode. I forgot about that until I tried it.