I used filezilla ftp to login to the domain, navigated to public_html folder, wp-content, themes, evolve, library, functions, functions.php. Use filezilla to download the file functions.php, to a location on your location and use notepad++ to open the file. The line # Roman stated above is all the way at the bottom on the page. Modify the credit link with your desired url and save the file. Upload the file back to the same location where it was previously downloaded.