Need to delete using CSS background image styles

Aloha :)

I have 2 dead CSS styles that are being included on every page of my website.

Both from abandoned design experiments last year.

I've looked everywhere - How do I flush these dead styles out?

The image being reference is long gone ... references to it are kicking up broken link errors.

---

.footer-widgets{background-image:url('http://geography.manoa.hawaii.edu/wp-content/uploads/2016/12/geog-footer.png');}

.site-info{background-image:url('http://geography.manoa.hawaii.edu/wp-content/uploads/2016/12/geog-footer.png');}

Much thanks,

Bill