Feature Image Size Adjustment

There are two image size functions:

add_image_size( 'listings-full', 1060, 9999, false );
add_image_size( 'listings', 560, 380, true );

In your theme, you’ll need to use the remove_image_size function (http://codex.wordpress.org/Function_Reference/remove_image_size) to remove those sizes.
Then after that, use add_image_size again with your own custom sizes.