Needs help properly setting up hard drive

I just installed the software that you need to download in order to use the hardware and clicked on the wrong set up option. It began sending all of my files to the hard drive and almost filled it to full capacity (I wanted to go through and clean out some of them, first). So, I cancelled the process, thinking I could go back and choose the files by category… But I haven’t been able to reach the set-up panel from the very beginning. Do anyone know how?

http://wdc.custhelp.com/app/answers/detail/a_id/3828/session/L3RpbWUvMTM2MDE0NjEwMi9zaWQvTWxCS0w5aWw%3D

Category back up.