I started with Atahualpa, great theme, but never heard of child themes, up until I saw that both WordPress and Atahualpa have a new version available.
There's warnings that I will lose all the changes I made when I do the update.
Of course I don't want that. So I read about child themes and started making one, but i'm kinda confused, cause how am I gonna get all the changes I've made in Atahualpa (including custom ones directly in the php files), into the child theme and afterwards be able to update both Atahualpa and WordPress?
Can I copy all the php files from Atahualpa directory to my child theme directory? Or is that not gonna do the trick?
I read about how to make child themes, but haven't found info on how to make your child theme if your website is already in place.
If anyone can be of help, I would be very grateful. Or if I missed information on this in another topic, please let me know, so I can continue my search there.

When you upgrade Atahualpa the only things you might lose are
1) changes you made to the theme files
2) header images you put in the atahualpa/images/header folder - you should copy these and put them in the same folder of the upgraded version

All settings you put in via the theme back end are stored in the database and will be carried over on an upgrade - you will not loose them.

of course you do do a database backup and backup the wp-contents folder before every upgrade...right???

Is there not a way to work around the header image placement every time there is an upgrade to the theme?

By the theme Back end - I presume you mean through Atahualpa Theme Options?

You can just use in image wrapped in a div in place of %image or a slider if you want rotating images.

see this thread written in 2010 in the FAQ forumHOWTO: upgrade Atahualpa to a new version