Snippet to modify breadcrumbs on WooCommerce product page

product-custom-breadcrumb.php

<?php

add_filter( 'woocommerce_get_breadcrumb', 'custom_breadcrumb_urls', 20, 2 );
function custom_breadcrumb_urls( $crumbs, $breadcrumb ){
    
	$customCrumbs = array();
    
	foreach ($crumbs as $key => $crumb) {
		$crumbLabel = $crumb[$key][0];
		$crumbURL = $crumb[$key][1];
		
		// SET CONDITIONS FOR NEW BREADCRUMB e.g. remove second level items
		if ( ($crumbLabel !== __('Shop', 'Woocommerce')) && ($crumbLabel !== __('Primary Category 1', 'Woocommerce')) && ($crumbLabel !== __('Primary Category 2', 'Woocommerce')) ) {
				$customCrumbs[] = $crumb;
		}
	}

	foreach($customCrumbs as $key => $crumb){
		switch( $crumb[0] ) { // Modify second level crumb items
			case "Crumb Label" : // If second level crumb item label is Crumb Label
				$customCrumbs[$key][0] = 'Crumb new name'; // Set new label 
				$customCrumbs[$key][1] = '/crumb-new-url/'; // Set new URL
			break;		
		}
	}

	return $customCrumbs;
}

?>