Modify Contact Form 7 output with filter/preg_replace. #wordpress #wpcf7

modify-wpcf7-output.php

add_filter( 'wpcf7_form_elements', 'rl_wpcf7_form_elements' );
function rl_wpcf7_form_elements( $content ) {

	// replace element with preg_replace	
	$rl_pfind = '/<label>/';
	$rl_preplace = '<label class="wpcf7-label">';
	$content = preg_replace( $rl_pfind, $rl_preplace, $content, 2 );

	return $content;	
}