Help needed to do minor edits to PDF file

I've browsed through the docs and googled for some examples but they
don't abound.

I want to create a small perl script to perform some re-coloring of
text and lines/boxes. Where can I find a starter sample that shows how
to browse the objects of a PDF file and modify their attributes
(stroke and fill colors in this case)?

I don't need the whole script done, but some pointers on how to browse
or even links to documentation/examples on how to browse objects in a
PDF file would be welcomed.

Also, while I'm at it, is there some way to "browse" through the
PDF::API2 classes, something similar to a type library viewer?

I'm using ActivePerl v5.8.8.

Thanks in advance for any help...