In order to remove your SiteBuilder site and create a new one with FrontPage or DreamWeaver or Expression Web you should follow the steps listed below:
1. Login to your SiteBuilder at the following url:
http://yourdomain.com/zen
where yourdomain.com stands for your domain name.
2. Navigate to the My Websites directory and click on the last button next to your site in the row. Clicking on the Delete button will permanently erase your website.
Then go back to your external site publishing software and publish as you normally would using FTP.