User blog:Patrick.vtap/Mod Code

I am hopefully, to teach myself how to code and texture things, am going to make a submod (is that even a thing?) to the LOTR Mod, adding a few things for my own amusement. I do not intend to plagiarize the mod, just adding a few things FOR MY OWN AMUSEMENT. So, how would I go about doing this, or is it even possible. I intend to add a few blocks for better building on my creative world. So how would you "access" the code, and is it possible to change it for my own computer.

Disclaimer: I have no intent to take any credit for this. I am just adding a few building blocks, and maybe releasing it to the public.