[TYPO3-english] change extension backend

[Stephan de Bruin]

Hello,

I want to change a textarea to a RTE (backend)in an existing extension 
(rtgdictionary). I've put the following in the tca.php file:

"description" => Array (
     "exclude" => 1,
     "label" => 
"LLL:EXT:rtgdictionary/locallang_db.xml:tx_rtgdictionary_terms.description",
      "config" => Array (
         "type" => "text",
         "cols" => "40",
         "rows" => "6",
         "wizards" => Array(
             "_PADDING" => 4,
             "RTE" => Array(
                 "notNewRecords" => 1,
                 "RTEonly" => 1,
                 "type" => "script",
                 "title" => "LLL:EXT:cms/locallang_ttc.php:bodytext.W.RTE",
                 "icon" => "wizard_rte2.gif",
                 "script" => "wizard_rte.php",
             ),
         ),
     )
),

after this I reinstalled the extension (with the edited tca.php file), 
but nothing has changed. The field is still just a textarea.

Am I missing something? Or should I approach this problem in a 
completely different way?

Thanks in advance.

Greetings,
Stephan de Bruin