Here is a guide to install PDF Mod on Ubuntu 13.04. You can install PDF Mod using the Ubuntu Software Center.
PDF Mod is a simple tool for modifying PDF documents. It can rotate, extract, remove and reorder pages via drag and drop. Multiple documents may be combined via drag and drop. You may also edit the title, subject, author and keywords of a PDF document using PDF Mod. Visit the PDF Mod Homepage.
To install PDF Mod click on the link below
When the software center is opened click on the Install button and enter your password to authenticate the installation. When PDF Mod is installed you can close the software center, to start PDF Mod press the SuperKey and type: pdf mod
Version: pdfmod 0.9.1-7
Total size: 6,2 MB to download, 18,7 MB when installed
License: Open source
How to open the apt link? Read this article.