alderman

@jpecsenyicki ,

Perhaps this will work for you if you add it to your functions.php file:

function mysites_new_pp_checkout_order_confirm_pagetitle( $title ) { 
    if ( ( 'Confirm your PayPal order' == $title ) && is_checkout() ) {
        $title = $title . '<p>My extra line of text</p>';
    }
    return $title;
}
add_filter( 'the_title', 'mysites_new_pp_checkout_order_confirm_pagetitle', 999 );