If you want to use this pack with the Complementary shaders: first, unzip the pack into its own folder, then double click with_shaders.bat, but do NOT double click it again, or it will mess up the folder names. If you do, you can still fix it manually, but it's less convenient. If you want to switch back to using this pack without shaders, double click without_shaders.bat, but again, do not double click it again for the same reason.