I want put the same password in 2000 pdf files automaticly

Good morning:

I have that make a pdf file, with many pdf files, and every pdf files have diferents security password. Before with the versión 4.0 of Adobe, I can select the directory where were all pdf files and changes the password of security easly, but in the version 8 and 9 I don't find this option.

And now I have make a new pdf file with 2000 pdf files, and I can´t all the pdf in the same file, I have that make diferents links between the pdfs files, but now I must put the same password in all the pdf file.
Before wih the version 4.0 I can put the same password, but now I don't konw, I have the version 9 of Adobe Standard, and I don't find this option.

Can anyboy heldp me?

Thank you.