Replace Vantage search form with Woocommerce Search form

I am trying to replace the vantage search form that is used in the menu search of the theme with a woocommerce search form. I came across this code from a while back.

This code is placed in menu.php:

<?php if( siteorigin_setting('navigation_menu_search') ) : ?>
				<div id="search-icon">
					<div id="search-icon-icon"><div class="vantage-icon-search"></div></div>
					<form method="get" class="searchform" action="<?php echo esc_url( home_url( '/' ) ); ?>" role="search" <?php echo get_search_form() ; ?>
					</form>
				</div>
			<?php endif; ?>

And this code is placed in functions.php:

function woo_wc_search_form( $form ) {
    $form = '<li class="search"><form role="search" method="get" id="searchform" action="' . esc_url(home_url( '/' )) . '" >
<input type="search" results=5 autosave="'. esc_url(home_url( '/' )) .'" class="input-text" placeholder="'. esc_attr__( 'Cerca', 'woothemes' ) .'" value="' . get_search_query() . '" name="s" id="s" />
    <input type="submit" class="submit" id="searchsubmit" value="'. esc_attr__( 'Search', 'woothemes' ) .'" />
    <input type="hidden" name="post_type" value="product" />
    </form></li>';
    return $form;

I am just looking for a bit of help with regards to where the code should be placed within the functions.php file. I can’t seem to figure it out.