I did a lot of searching, but I finally figured it out. What you do is go into your drive, look under the file marked "Steam", then "userdata", then the games' number (found on the Steam page or by hovering your cursor over the desktop shortcut), then "remote", and when you arrive at a file marked "saves", delete it. And you're done!

Also (I can't believe I forgot this), be sure that your game isn't synced to the Steam Cloud or the above steps won't work.