用函数更改特定的插件数组

Question

I would like to change an argument in array form an existing plugin, however, the plugin has a file that contains a gazillion arrays which are not specified. How do I call the right one? Do I count them? This is a snippet of the actual function:

public static function reward_system_admin_fields() {
    global $woocommerce ;
    $categorylist = fp_rs_get_product_category() ;
    return apply_filters( 'woocommerce_rewardsystem_social_reward_settings' , array(

    //gazillion arrays//

    ),
    array(
        'name'     => __( 'Facebook URL Selection' , 'rewardsystem' ) ,
        'id'       => 'rs_global_social_facebook_url' ,
        'std'      => '1' ,
    )
}

From the above code I want to change the 'id'. My beginning is as follow:

function change_one_of_a_gazillion() {
    // array action
    return;
}
add_filter( 'woocommerce_rewardsystem_social_reward_settings', 'change_one_of_a_gazillion', 15, 2 );