It would be great if you told us what program you are talking about. And it would be even better if you posted your question in the appropriate product forum, which you may find here:
This forum is only for discussions on the forums themselves.
I am sorry, but at the top of my session it says I am in the Adobe Reader Forum. That is why it is assumed I am talking about Adobe Reader.
Adobe Reader is not able to do what you want. It cannot change pdf files.