BP Social Theme: can you tell me where the HEADER IMAGE of my CUSTOMIZED Social Theme sits? (So I ca

Hello,

I have a quick question for you:

I had my Social Theme pretty heavily customized:

See http://TheJazzHang.com

MY QUESTION: could you tell me where that CUSTOM HEADER IMAGE of mine sites, so that I could swap it? (Added a few words to that header; same dimensions, though.)
Also, definitely would wanna do that in the CHILD THEME, so it's upgrade-proof.

The developer who did this customization for me is not reachable right now, so I reaching out here.

Thanks for pointing me in the right direction!

Best,

Falk