You need to download and install python in order to run the script. https://www.python.org/downloads/ Also, not sure why that link isn’t working. I’ll remove it for now.
After you run the script and get the world_2a-decompressed.bin, delete the original (or rename it to world_2a-original.bin). Then, rename world_2a-decompressed.bin to world_2a.bin, and open it with Notepad++’s HEX-Editor plugin, or any other HEX editor of your choice (but since you already have Notepad++, the plugin is probably easiest).