Download the zip file, unzip it, open it. In the "game" folder, copy the script.rpy file and the "images" folder. Paste them into your own project (inside your "game" folder). From there, you can decide when the minigame appears in your game using any .rpy file. If this is too confusing for you, I recommend getting some more practice in RenPy first, maybe try finishing a short visual novel to get used to it. Hope this helps!