Solution:
1.) I understand that you’ve said that you don’t want to use a WordPress plugin, but if possible you really ought to checkout better search replace it should do exactly what you’re describing.
2.) You could run this SQL code in your database management system:
UPDATE wp_options SET option_value = replace(option_value, 'http://cjdrafts.info/quadrantgallery', 'http://cjdrafts.info/art') WHERE option_name = 'home' OR option_name = 'siteurl';
UPDATE wp_posts SET guid = replace(guid, 'http://cjdrafts.info/quadrantgallery','http://cjdrafts.info/art');
UPDATE wp_posts SET post_content = replace(post_content, 'http://cjdrafts.info/quadrantgallery', 'http://cjdrafts.info/art');
UPDATE wp_postmeta SET meta_value = replace(meta_value,'http://cjdrafts.info/quadrantgallery','http://cjdrafts.info/art');