I was using my external in my Xbox One and selected format and I hope that didn't delete everything or something, but now my HDD isn't readable on my Mac. I need to format it. I already looked for how to do this. It says to use the Disk Utility and select Erase. The instructions in the dialog box there says go to Security Options to prevent recovery or something. I don't know...I'm iffy on this...I have nearly the entire 1 TB full. I don't want to risk losing anything.