Pain? Not even close.
Download a torrent program, like the super simple Bittornado (there are better ones, but this is simplest), install that, then search for a torrent site that has what you want. Download the torrent file and double-click it. Tell it where you wish to save the files, then let it run. If you find the site most of us use (again, I can't tell you), you'll have a nice fast download, even for a 16-17 GB download.
Once it's complete, let it keep running so that you're giving back to the community. You'll be uploading at this point and making the files available to others with minimal effort. Try to let it reach at least a 1.0 ratio.