How do I add the data-toggle=”modal” data-target=”#myModal” attribures to a WP Nav bar?

I’m new to WordPress so please be patient!
I’ve created a template in html5/ccs3 and am in the process of trying to make a wordpress template out of it.

In my navigation menu (in html) I have a social menu that opens 3 different modals:

<social-icons>
  <div class="navbar-collapse collapse">
    <div class="btn-group nav navbar-nav navbar-right" role="group">
      <button type="button" class="btn btn-success navbar-btn facebook"><i class="fa fa-facebook-official btn-icon"></i></button>
      <button type="button" class="btn btn-success navbar-btn twitter"><i class="fa fa-twitter-square btn-icon"></i></button>
      <button type="button" class="btn btn-success navbar-btn instagram"><i class="fa fa-instagram btn-icon"></i></button>
      <button type="button" class="btn btn-success navbar-btn google"><i class="fa fa-google-plus-square btn-icon"></i></button>
      <button type="button" class="btn btn-success navbar-btn vine" data-toggle="modal" data-target="#vineModal"><i class="fa fa-vine btn-icon"></i></button>
      <button type="button" class="btn btn-success navbar-btn snapchat" data-toggle="modal" data-target="#snapchatModal"><i class="fa fa-snapchat btn-icon"></i></button>
      <button type="button" class="btn btn-success navbar-btn periscope" data-toggle="modal" data-target="#periscopeModal"><img src="https://wordpress.stackexchange.com/questions/210345/assets/img/periscope.png" class="periscope-img"/></button>
      <button type="button" class="btn btn-success navbar-btn email"><i class="fa fa-envelope btn-icon"></i></button>
    </div>
  </div> <!-- nav -->
</social-icons>

I’ve created the menu structure in WP and allocated all of the css classes, but I can’t figure out the way to add the other attributes, specifically the data-toggle and data-target attributes.

I’ve seen explanations that sound similar but nothing that I can get to work, and most of what I have found is several years old now.

If anyone could enlighten me I’d be very greatful!
Thanks in advance

PHP way:
Add the following to your functions.php file.
Filter nav_menu_link_attributes:

add_filter( 'nav_menu_link_attributes', 'my_menu_atts', 10, 3 );
function my_menu_atts( $atts, $item, $args )
{
  // Provide the id of the targeted menu item
  $menu_target = 123;

  // inspect $item

  if ($item->ID == $menu_target) {
    // original post used a comma after 'modal' but this caused a 500 error as is mentioned in the OP's reply
    $atts['data-toggle'] = 'modal';
    $atts['data-target'] = '#myModal';
  }
  return $atts;
}

jQuery way:

<script src="https://code.jquery.com/jquery-1.10.2.js"></script>
<script type="text/javascript">

    jQuery(document).ready(function() {
        jQuery('#menu-item-365').find('a').attr('data-toggle', 'modal');
        jQuery('#menu-item-365').find('a').attr('data-target', '#myModal');
    });
</script>