Open
Run the downloaded file from your Downloads folder or from the downloads bar in the top-right corner of your browser.

Your download has started. If it didn't — pick a build:
Run the downloaded file from your Downloads folder or from the downloads bar in the top-right corner of your browser.

Follow the installer steps. Once it's done, a shortcut named «KLauncher» will appear on your desktop.

Pick the Minecraft version you want to play and hit «Play». The launcher will install everything for you.
