>I need to change some values in a XML document, just like a .ini file.
>Is there a library/tool who can handle that?

You can use XMLToCursor() to "import" it to a table then modify it and send it back with CursorToXML().
You can just open it as text in an editor (or an edit box) and do the mods manually.
You can get an XML Editor
http://www.webattack.com/get/xmlnotepad.shtml
http://www.oxygenxml.com/
http://www.xmlcooktop.com/
http://www.iol.ie/~pxe/