Delete All Old Youzer Options From Database.

yzc_delete_all_youzer_options.php

<?php

/**
 * Delete All Old Youzer Options From Database.
 */
add_action( 'init', 'yzc_delete_all_youzer_options' );

function yzc_delete_all_youzer_options() {

    global $wpdb;

    // Delete Old Fields
    $options = $wpdb->get_results( "DELETE FROM " . $wpdb->prefix . "options WHERE option_name Like 'yz_%'" );
}