API integration with Ultipro or Cognos Analytics

I am hoping to learn about how to set up an API call to retrieve a report that is in our UltiPro (HRM) system through Cognos Analytics. We have a web services account set up already and I have the API information i need. I’ve downloaded the API package but from here I am lost. Has anyone every done this? Or does anyone know of any documentation on how to do this correctly?