Replace search menu with Predictive search plugin

Hi there,

I would like to change the original search function from the Neighborhood theme with the predictive search plugin.
The plugin is active and I also add the code
<?php if(function_exists(‘woo_predictive_search_widget’)) woo_predictive_search_widget(); ?>
to header.php
Unfortunately this code does activate the plug in, but not at the right place.
Does anyone know how/where to replace the search menu in the neighnorhood theme (keeping the neighborhood style would be a plus).
Thank you very much for your collaboration

Fabio

ps. this is my website: http://timeforyourskin.com/
and this is the url of the plugin: http://a3rev.com/shop/woocommerce-predictive-search/

http://wordpress.org/plugins/woocommerce-predictive-search/