title: replace string in PDF document (ITextSharp or PdfSharp)
body: <p>We use non-manage DLL that has a funciton to replace text in PDF document (<a href="http://www.debenu.com/docs/pdf_library_reference/ReplaceTag.php" rel="nofollow">http://www.debenu.com/docs/pdf_library_reference/ReplaceTag.php</a>).
  We are trying to move to managed solution (ITextSharp or PdfSharp).
  I know that this question has been asked before and that the answers are "you should not do it" or "it is not easily supported by PDF".
  However there exists a solution that works for us and we just need to convert it to C#.
  Any ideas how I should approach it?</p>