@Ludwik, that is a link to the forum thread. You need to go to a post in that thread and download the ZIP files. Once you do that, place them in your replays folder inside a separate folder. The subfolder's name should relate to the game (who fought, is it a team game, free for all or 1v1, etc.).
Then, in game, you go to
Single Player -> Replays
There, you should find your replay.