JustShop Theme already includes an awesome in-built breadcrumbs, but if you prefer to use Yoast, please follow these steps:
Disable the default breadcrumbs from Theme Options –» General Settings –» Display Options.
Open up your theme's functions.php file and put the following code just before the text "Don't add any code below here."
if ( function_exists('yoast_breadcrumb') ) {
add_action('woo_content_before','JS_yoast_breadcrumbs',10);
}
if ( ! function_exists('JS_yoast_breadcrumbs') ) { function JS_yoast_breadcrumbs() {
yoast_breadcrumb('<section class="breadcrumbs-wrap"><div class="breadcrumb breadcrumbs woo-breadcrumbs">','</div></section>');
}
}