Q: How do I erase information in the disk utilities?

Hi, I was installing an external software, after it the computer shut down and it didn't re-start normally, I had a some options in the disk utilities and I looked for information and found that my software was broken. I have four options 1. Restor from the time machine 2. Reinstall OS X 3. Look for help 4. Disk utilities. I tries to reinstall OS X but I don't have enough memory to do it, so I want to know how to erase information from my disk utilities without erasing all? My last time capsule doesn't have an important paper in which I was working. If you have any other option or idea please let me know. I have Mountain Lion.

Thanks.