First of all you have to install the latest patch for your FM 2005. It can be found on
http://www.sigames.com in downloads section.
Then download the Revolution Update (if you haven't done it yet) and click on the exe. The main screen appears and it says that you have to choose an destination directory. Now, depending on where you have installed your game you simply have to choose that directory (default should be: C

Program Files\Sports Interactive\Football Manager 2005\data\db ). Then simply click "Instaluj" wchich stands for "Install" in english and the installation will proceed.
Oh, one more thing: "dalej" means "next" if you havent figuered it out yet