These are the required files used by all mods for AWSW.
Step 1. Unzip the downloaded file. Inside you should find 2 folders and a .rpy file.
Step 2. Go to your game files ~/steamlibrary/steamapps/common/Angels With Scaly Wings/. Open the folder called "game".
Step 3. Copy and paste the 2 folders and bootstrap.rpy file you just dowloaded into the "game" folder.
Step 4. Launch the game to make sure there are no errors. If installed correctly, there should be a "Mods" button in the lower left corner.
(Optional) Step 5. Download another mod and place it in the "mods" folder. Launch the game and press the "Mods" button on the main menu. If you installed the mod correctly, it should be listed in the text box that appears.