I actually don't remember the name of the site (because I downloaded them 3 years ago...) but I remember in their tos that "you are free to do whatever you like, except for redistributing any or all of them commercially" (and yes, I read the tos before using a site...).
Any image can be a smiley. Just upload it to your server, go to the Smilies area, point it in that location, and it's a "smilie". There isn't really anything to install. He added a SQL file, but that isn't necessary if you upload them to your own area.