Not being an expert in Linux/Ubuntu, I had to install from scratch today and messed up w/file permissions.

The thing is that, when backing everything up before reinstalling, a couple of important documents couldn't be copied to the external drive, so I used gksudo nautilus to be able to.

Now I've copied them back and I can't use them. They are locked, a lock icon appears on a corner and the original error message shows again.

Is there a graphical/easy way to set file permissions back to normal?

I've read about chmod fchmod and chown and I would like to avoid them if possible. If there's no choice, can any of you please give me a quick example on how to use it?

Thank you so much Ub. Community!