[Zope] Changing document type how-to: another idea

Hi, It exist a mini-how-to (I loose URL) about changing document type via ZMI. But it is not useable for many documents. After I was uninstall "HTML Document" product, I have lot of files that have "HTML Document" type instead of File or "DTML Document". I have try another method via FTP to change into "DTML Document". 1. copy files from Zope via FTP to local filesystem 2. delete files in Zope (via FTP) 3. and copy files from local back to Zope via FTP But these throw away all properties (same as method in mini-how-to) and does not allow to change into another than "DTML Document". Regards J. Lukesh