5
I think I have to write complete sentences!
What I meant was: Turn the xoops-editor area into a wysiwyg-editor area.
You have to look at modules / system / admin / blockadmin / blockform.php.
You have to adapt this line
$textarea = new XoopsFormDhtmlTextArea(_AM_CONTENT, 'bcontent', $block['content'], 15, 70);
The xKoivi-editor has a good documentation on how to make this dhtml-area wysiwyg.