Put your gsc-files inside the mods-directory (so the _rank.gsc would go into the mod\maps\map\gametypes\ directory).
You can edit your mod and reload it via the \map_restart in the console. No need to restart the game.

Run the exe.
Run the game.
Play your mods.

Known bugs:
At this moment files that do not get called by the game will not get loaded so you have to add everything into existing files. Sorry.

Credits:
SuperNovaAO @ It's Mods

Inspired by AgentGOD