Hello!
Thank you for creating so beatiful and good-work theme.
I have a little problem. I want to replace several images which are used for social icons but couldn’t find them. Where are they stored?
These are not icons but font icons and are packaged as a whole. For more information you can check http://genericons.com/
You can replace them via CSS as long as there is alternative icon available form Genericons. If you want to replace it entirely it requires some work and some coding skills.