[Zope] Editing downloaded + installed product?

[Stefan Hoffmeister]

I have downloaded a nice-ish looking product, all complete with .dtml,
.py, .gif etc files.

Now I would like to take this product, strip it down to the barest bones
to understand its (and Zope's) inner workings, then resurrect it to learn
developing at least something stupid and mindless.

Problems:

a) I see no way how to "modify" any installed product.
   (I suspect that this cute "closed box" symbol means: no way - but
    I have yet to find docs to this respect)

b) I do not seem to be able to get a copy of this product into
   Zope in an "editable" form.

c) I do not seem to be able to add some "plain", straight-forward Python
   code to a ZClass that I have created from scratch; only adding an
   External Method *on disk* can be added?

   (and this finally leads us to...)

d) I suspect that even if I modify all that on disk I will have to
   restart ZServer each time?


Could somebody please shed some light on this?

Thanks!