Change search function in Blackbird

Hi, I would like to change the wordpress search function to the google and place it exactly where the current search bar is. The code from Google is:

[ Moderator Note: Please post code or markup snippets between backticks or use the code button. ]

<script>
  (function() {
    var cx = '017714179833060850376:we7jcv8iuso';
    var gcse = document.createElement('script');
    gcse.type = 'text/javascript';
    gcse.async = true;
    gcse.src = (document.location.protocol == 'https:' ? 'https:' : 'http:') +
        '//www.google.com/cse/cse.js?cx=' + cx;
    var s = document.getElementsByTagName('script')[0];
    s.parentNode.insertBefore(gcse, s);
  })();
</script>
<gcse:search></gcse:search>

Can I just replace this in the search.php form via FTP or can I insert it in the theme header.php ?

Any help would be gratefully received.

Regards