Replacing Site Title with Personal Logo

This is a great theme! I just have one question: how to replace the site title with a personalized logo, hopefully by using the custom css options for the theme?

I don’t want to replace the entire header image like in the “replace header image” option, just replace the site title and/or site description with a logo that will still have a link to the home page.

If anybody out there has an answer I’d really appreciate it.

Thanks,