editing a PDF [Re: emacs 30.5.0 editing epub]

[address@hidden]

On 3/16/23 9:13 PM, Michael Heerdegen wrote:
> I managed to copy an pdf-File into an epub Archive.  Opened the
> archive and opened the pdf using doc-view.  I was not able to provoke an
> error.  Saving worked successfully however I tried.
>
> Michael.

How does one edit a PDF file in emacs?  When I downloaded 
https://www.gnu.org.ua/software/direvent/manual/direvent.pdf, loaded it 
into emacs, and tried to edit it, I could see it it and read it, but I 
couldn't even highlight a part of the text so I could copy it... nor 
could I make any changes to it.