Ableton bundles from Multitracks.com will come as .alp files which is Ableton's version of a zip file.
1) Once you have opened the folder from the website, navigate to the ALP file and double click
2) From here you will be prompted for an install destination. Choose the place where you want these patches to live.
3) Once you choose a destination, click "open" and the bundle will begin the Unzipping process.
4) As soon as the install process is complete you will see a blank Ableton set. You haven't done anything wrong, don't panic. Now you will just need to navigate to the folder where you saved the bundle and open the .als