Hi Vitemerius,
First, you can install this plugin: https://www.ads-software.com/plugins/header-and-footer-scripts/
Then paste the following code in your Admin Panel > Settings > Header and Footer Scripts > Scripts in header:
<script type="text/javascript">// <![CDATA[
jQuery(document).ready(function(){
jQuery('#logo a').attr('href', 'https://www.google.com');
});
// ]]></script>
Thanks!