$re = '/[0-9]{5}$/';
$str = '{
"Token" : "VwAMVWXTakkdffdkEj1I9IiTr8DlYa89fK4yimmQNWSi87980tIY1qBb1Qbs1FU9CfZHWMMlTed3hHOaBD7vJGNh9ZugFZuANtAomk17vIjg3Zgl1Fp0kulb6UTsbnkyyGNwNMGR"
}';
$subst = "";
$result = preg_replace($re, $subst, $str);
echo "The result of the substitution is ".$result;
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for PHP, please visit: http://php.net/manual/en/ref.pcre.php