PDF processing before delivery

Hi,

There is no easy way to do this.
To be able to modify PDF files in PHP, you need to use a library like Zend PDF or FPDF/FPDI:
stackoverflow.com/questions/7364/edit-pdf-en-php
Note however that as some pointed there, it might be impossible with some PDF files as there are many ways PDF files can be generated (for example with DRMs).
And since you want to integrate this in HikaShop, you can use the event onBeforeDownloadFile of HikaShop in a custom plugin to add your PHP code using these libraries:
www.hikashop.com/support/documentation/6...onBeforeDownloadFile
So it requires advanced skills in PHP and time to put in to know how to make a Joomla plugin and how to use these PDF libraries and it might not work with some PDF files.