Move required span of fields outside the label
You can achieve this goal via implementing theme_form_element_label.

I hope you already know how to implement or override theme.

e.g. 

function MYTHEMENAME_form_element_label($variables) {
  $element = $variables ['element'];
  // This is also used in the installer, pre-database setup.
  $t = get_t();

  // If title and required marker are both empty, output no label.
  if ((!isset($element ['#title']) || $element ['#title'] === '') &amp;&amp; empty($element ['#required'])) {
    return '';
  }

  // If the element is required, a required marker is appended to the label.
  $required = !empty($element ['#required']) ? theme('form_required_marker', array('element' =&gt; $element)) : '';

  $title = filter_xss_admin($element ['#title']);

  $attributes = array();
  // Style the label as class option to display inline with the element.
  if ($element ['#title_display'] == 'after') {
    $attributes ['class'] = 'option';
  }
  // Show label only to screen readers to avoid disruption in visual flows.
  elseif ($element ['#title_display'] == 'invisible') {
    $attributes ['class'] = 'element-invisible';
  }

  if (!empty($element ['#id'])) {
    $attributes ['for'] = $element ['#id'];
  }

  // The leading whitespace helps visually separate fields from inline labels.
  return ' &lt;label' . drupal_attributes($attributes) . '&gt;' . $t('!title', array('!title' =&gt; $title,)) . "&lt;/label&gt;" . $t('!required', array('!required' =&gt; $required)) . "\n";
}


Put this function on template.php