This is my entry to the NSMBHD 2017 Winter Contest. 

1. Patching your ROM
Firstly, download DeltaPatcher (my suggestion) or any xDelta patcher.
Get a NSMBDS ROM, specifically 0434 - New Super Mario Bros.(Psyfer).nds
Next, extract the PATCH.xdelta in this archive and the ROM in the same directory of the patch. (just for convenience)
Patch the ROM (you should probably backup the original file first) and you're done!!

I hope you enjoy my entry, as I put alot of my time into this.
Thanks for reading, newluigidev.