Update PDF metadata

From http://askubuntu.com/questions/401114/which-is-the-best-pdf-metadata-viewer-for-ubuntu

1. View pdf metadata for a file called Example.pdf:
   

   pdfinfo Example.pdf  
   

2. Edit existing metadata in the terminal using nano editor:
   

   pdftk Example.pdf dump_data output Metadata-output.txt
   nano Metadata-output.txt  
   

3. Update metadata:
   

   pdftk Example.pdf update_info Metadata-output.txt output Example-new.pdf