It's a bit annoying, but you have to take the file, extract it, and then move the "pictures" folder from the extracted folder into the "img" folder of the game. It's different from most since it has two layers of "img" folder inside the compressed file for some reason. You should know you're doing it right if your device pops up a message saying that a file with the same name already exists in the folder, and asks if you want to replace it (which you should say yes to.)