Metasploit PDF Backdoor Help

I am very new to Metasploit, and after searching around I thought I might aswell start with learning how to utilize the exploit in Adobe's PDF viewer. The instructions --

" As you can see from the screenshot above, Metasploit requires us to provide an existing PDF where it can embed the Meterpreter. Let's set a file named chapter1.pdf, presumably some class notes (make certain that this file was created with Reader 9 or earlier), to our INFILENAME option. "

This makes things clear, except for how I can create my own PDF file on an outdated version of Acrobat. I need a version lower than or equal to Acrobat 9 - And in hoped to test this exploit, was searching around for a PDF online, that was created with Acrobat <9. I have no way of knowing if it was created with Acrobat 9, and am lost as to how I can create my own. Any help ? How can I make a PDF file on a previous version of Acrobat so I can embed the Meterpreter inside it ?

P.S. I got into this very recently and Null-Byte has been my go-to for quick learns and great practice. I have my own classes I take, but other than that, this is a fabulous. Thanks for every bodies work.