@James Kirk
Oh, I missed the link in your previous post!
Great, I've solved the child theme part now. And got it working with a style.css file.
But I dont understand what I need to do to be able to change parts of the header.php!
I tried adding a header.php file in my child theme and then just simply adding the code that you gave me, and saved. That messed the whole website up.
How do I go about doing this? I'm sure it's some obvious way that I'm missing but can't figure it out..
Thanks a lot!
Best,
D