This function will replace a given text with a new value in a serialized string

serialize_replace.php

<?php
/**
 * This function will replace a given text with a new value
 * in a serialized string
 *
 * @param string $input serialized value to seek
 * @param string $search text to be replaced
 * @param string $replace replacement text
 * @return string new serialized string
 */
function serialize_replace($input, $search, $replace) {
  $ua = unserialize($input);

  $replace_callback = function (&$value, $key, $data) {
    if(!is_int($value))
      $value = str_replace($data['search'], $data['replace'], $value);
  };

  array_walk_recursive($ua, $replace_callback , ['search' => $search, 'replace' => $replace]);

  $b = serialize($ua);
  return $b;

}