I'm following this tutorial (sorry, it's in Spanish, if you need more info, let me know) and, as you can see the bootloader step is before the security copy step.
I went to the details of that bootloader step and did what it says here and when my phone restarted I found I lost all my files.
However, I could recover some of contacts and apps, I think because of my gmail account. Is there any way to recover also the files like pictures I had in the phone memory? Maybe it's easier after being root user? Thanks!