[Zope] Zope update

Hi, I want to update from Zope 2.7.4 to Zope 2.7.6 What is the easiest way? Unfortunately there is no description of how an update of Zope is done. I'm running Plone on it. I tried to newly install Zope 2.7.6 and then copied the backed-up Data.fs file and the content of the Products folder. It didn't work very well. There should be no version conflicts with Plone as I checked on the Plone web site. Thanks for any advice! Josef