1. Find a map that you want to download. You did that, it's this one you want! Link is above.
2. Download The map to a place that you will remember (Downloads folder, Dekstop, wherever)
3. Unzip or Unrar The file using your archiver of choice (WinRAR, 7Zip, etc).
4. Copy The folder that was unzipped, unrared, etc., and navigate to your Minecraft saves folder:If you're running Windows, your saves are located here:Press The Windows Key and R at The same time. In this dialogue type (or copy and paste) The following%appdata%.minecraftsavesIf you're running on a Mac, your saves are located here:/Users/*username*/Library/Application Support/minecraft/saves/If you're running Linux, your saves are located here:`/.minecraft/saves
5. Paste The folder and re-name it if you desire.
6. Play Minecraft with The Adventure Multiplex map installed!