Though more Php then Contao, Replacing term TYPOlight in DB

We have site as you must have seen long under showcases http://www.web-praesenz.ch.
In whole of the website there are multiple occurance of word 'TYPOlight'. I wanted to have it replaced with word 'Contao', so I thought instead of replacing it one by one, why not per script.
I set to write a script and almost done it with SQL some thing like

Code:

---

        foreach($tables as $table)
        {
                        while($row = mysql_fetch_field($table))
                        {
                                $tn = $row->table;
                                $fn = $row->name;
                                $sql = "update $tn set $fn= replace($fn,'TYPOlight','Contao')";
                                mysql_query($sql);
                        }
        }

---

Yes it replaced every occurance of word 'TYPOlight'. Since many fields are serialized it didn't work well. I even thought for a while and changed the SQL syntex to

Code:

---

                                $sql = "update $tn set $fn= replace($fn,'s:9:\"TYPOlight','s:6:\"Contao')";

---

which didn't work. Any suggestion for a lazy man here.

unserialize the data first an loop through the array? Maybe? :)

Or make an sql dump, replace whatever needs to be replaced and import it back afterwards :)

Thanks for tips,
Actually my first code worked well. On the places where it fails, which is only few of them (to my luck), i think I'll update it from the backend.
unserialize the data first an loop through the array may be done, but I didn't do it thinking it is a lot of overhead.