How do I use this multicart compiler https://github.com/ClusterM/coolgirl-multirom-builder. I'm kinda stupid when it comes to cmd crap so if you can explain it like I'm 5 or something. lol thanks in advance to anyone willing to help.

Yeah about that, I'm having trouble finding out where I put the commands, is it cmd or mysys2 and how do I get nes tiler to work? It says it doesn't have a program to open it properly, how do I use the prepare cmd if I can't find it or put it in the proper respiratory?Read the manual, scroll down the repository and you'll find the instructions.