[Zope] How To Convert Files To Page Templates?

Hi; I'm redoing a bunch of documents on a Zope site on my PC and I realized it would be easier to simply delete all the old ones and upload all the new ones. But if I do that, they'll load as "files", not "page templates". I know there's a way to convert between the two, but I don't remember how. Can someone help? TIA, Nancy