I have found the relevant icons in the theme/images folder and edited then in Photoshop. However the original icon still remains. is there any thing else that I should be doing? I have not changed the file name when I re upload via ftp to the images folder
Yes, the icons for social media can be changed from theme/images folder. Make sure you clean up your browser cache and also make the required image or code changes only through child theme so that your changes won’t get lost when you update the theme.