- str_replace: documentation ( source)
<?php
$test = "as";
$text = $text . '[kav ““”” - ““””]';
$doubleQuotesToReplace = array("“", "”", "“", "”");
$doubleQuotes = array('"', '"', '"', '"');
$text = str_replace($doubleQuotesToReplace, $doubleQuotes, $text);
echo $text;