Getting and Editing XML
So good news, you already have reached a point of success! Visit Plone's front-page in a browser and add manage_FTPget to the URL, as shown in the URL bar below:

Ahh, look at all that XML goodness, ain't she beautiful? But can we edit an existing entry? Let's use the cadaver command-line DAV tool and find out:
$ cadaver http://localhost:8880/atxml/
$ edit front-page
Note the usage of the WebDAV port number!! Depending on your editor settings, the second command will give you an editor such as vi. Change the value of the <dc:title> element, then save and exit the editor. cadaver will send the changes to Plone and unlock the resource.
Re-open the Plone front page in a web browser. You should see your new title. Cool, eh?
Some notes on this:
- Eagle-eyed observers will note that the body field was, errm, how shall we say this....encoded. In the case of Marshall 0.6, if a field's contents are HTML, the Marshaller puts the content in a CDATA. Why? Because we can't promise that the HTML is well-formed XML. Future versions of Marshall might revisit this policy. Note that image and file field contents are currently not serialized.
- cadaver has a helpful readline mode, if your compilation supported it.
- This XML format is in flux! Sidnei and I are discussing how to get more "meaning" out of Plone, in a way that fits the median of expectations.
I like using the oXygen editor, as noted above. With oXygen I can open the Plone site, browse to front-page, and edit the content in a real XML editor. I can even download the Relax NG schema for Marshall and validate before saving.
In this next screenshot, I show browsing the contents of the Plone site using oXygen's WebDAV browser:

I double-click to open front-page and tell oXygen that this is an XML document (lack of file extension means it couldn't guess). In the next screenshot, I have the front-page, exported as ATXML, open for editing. I have changed the dc:title and I have also associated the Relax NG schema with this page, thus giving me the inspector on the right:

Finally, I show the schema validation in action. I mistakenly change the id attribute on a field to be xid, which is not allowed in the schema. Note the red underline, the completely accurate warning message in the status bar, and the appearance of the right-hand inspector pane:
