Help [Help] Android 4.0.4 update

Can I update my GN over data connection directly here in the Philippines from the phone itself?

If yes, how? If no, any options and how?

I read something of how to update manually but I couldn't understand it well. I have also downloaded a file that I am using the 'yakju' product code or of something.

I am currently using the 4.0.2 version... and I am quite worried if it is good to update GN or stay with the current version I have.