How to unhook a function in Woocommerce Template?

Question

You need to unhook the function from that action specifically:

remove_action( 'woocommerce_review_before_comment_meta',
               'woocommerce_review_display_rating', 10 );

(e.g. look for the opposite add_action() line in includes/wc-template-hooks.php)

You’ll also need to make sure that this is run after WooCommerce has loaded and added the action you’re about to remove, e.g. place this in a plugins_loaded hook:

function unhook_display_rating() {
    remove_action( 'woocommerce_review_before_comment_meta',
                   'woocommerce_review_display_rating', 10 );
}
add_action( 'plugins_loaded', 'unhook_display_rating', 10, 0 );