I've downloaded some of the PPT templates in the downloads, e-learning, ppt area. Once the zip is extracted, I'm left with directories that contain images, masterslides, pptx etc. How do I add to PPT? I can't just add the one masterslide to my ppt can I? It seems that PPT to add a new template wants a single file as it's source and I'm not sure which one to point to?