go to tucows or download dot com or some other freeware site, search for .pdf and then sort by freeware. There are a few pdf editors out there for free. They are pretty simple to use, just like Microsoft Word, except they edit .pdf files
Sounds like you're after the full version of acrobat. Some apps (I think Word can do it) can import PDFs, but the formatting, layout, and fonts won't always turn out exactly the same.