Change the HTML template for a specific crumb in the breadcrumbs trail

add_filter( 'aioseo_breadcrumbs_template', 'aioseo_breadcrumbs_template', 10, 2 );

function aioseo_breadcrumbs_template( $templateItem, $crumb ) {

	if ( is_a( $crumb['reference'], 'WP_Term' ) && 'uncategorized' === $crumb['reference']->slug ) {

		$templateItem['template'] = '<span class="aioseo-breadcrumb">

			#breadcrumb_label

		</span>';

	}

	return $templateItem;

}