Ok, I'm going to attempt to be as tactful as possible here.
Based on the screenshot, it looks like you are trying to change the security on the pdf document to "No Security" and you want someone on this forum to provide you with the password so you can circumvent the protection the author put in place. This is also known as copyright infringement. Asking for help to do such a thing on this forum is a violation of the forum rules. If you want the password that badly, I suggest you contact the authors. Their emails are at the bottom of the readme in the zip file you downloaded from the link TSPenguin gave you. Otherwise, you're barking up the wrong tree.
---------- Post added at 01:27 PM ---------- Previous post was at 01:26 PM ----------
If that is not the case, I apologize. I'm just basing this assumption on what I see in the screenshot.