Where Do I Delete a Modified Header 2016 Theme

I’m helping a friend out & I suspect that her Twenty Sixteen theme has been modified. One or more of these modifications is causing her problems with viewing it on her Iphone. I just deleted the video on the home page.

The other thing that I want to do is to delete the header with her name Kelly Bouchard (w/ a pink K) that stretches across the entire width of the page. The original Twenty Sixteen theme doesn’t seem to allow for that wide of a header. I’m assuming that this is the header.

Where do I go to alter or delete this? I’m looking at the template.php files but at a glance these seem to be the standard code from the original template or at least for the header.

Thanks,

Stephanie