How to rotate then save a PDF document?

[Richard Owlett <rowlett@cloud85.net>]

I use MATE and thus use Atril as viewer.
Typically I have no need to modify PDF documents.
I received a reading a long reading list which needs to be rotated left 
to be read. Atril rotates it but does not save it as rotated.

What's the simplest tool to permanently rotate that specific document?
TIA