Image Optimization

I am using GTMetrix.com to test the performance of my site.
One thing it points out is that the image in the footers basically the icons for the RSS feeds are not optimized. I searched through the editor to find these items with no luck. The two recommendations from GTMetrix are below. Where can I find these items in the editor in order to replace or remove them for better performance?

Losslessly compressing https://pinellasbusinessdirectory.com/wp-content/themes/raindrops/images/rss.png could save 31.0KiB (97% reduction). See optimized version

Losslessly compressing https://pinellasbusinessdirectory.com/wp-content/themes/raindrops/images/footer.png could save 24.3KiB (91% reduction). See optimized version