SDL2: https://www.libsdl.org/download-2.0.php just download the appropriate development library for your compiler and place it in "./SDL2/"
libogg: https://xiph.org/downloads/ (libogg) download the libogg .zip file and unzip it in "./libogg/", then build the library as a framework, and include it in the xcode proj
libtheora: https://xiph.org/downloads/ (libtheora) download the libtheora .zip file and unzip it in "./libtheora/", then build the library as a framework, and include it in the xcode proj
Open the Xcode project and build it from there.