Tutorials
We now have a video tutorial on how to install songs that are not in .smzip format
How to install songs in Stepmania
The easiest type of stepmania songs to install are those in .smzip format. All you have to do is double click on the file and it automatically installs. Most of the files you download from this site will be in smzip format(that's why we are better than other sites;))
Unfortunately, not all song packs you download will be in the convenient .smzip format. Some of them will just be regular zip files. To install regular zip files, you first need to open up the stepmania folder in Program Files. There should be a shortcut to this in the start menu.
After you have done so, double click on the songs folder. Then, unzip your zip file song pack. Copy the folder with the song(s) in it from the zip pack to the songs folder in the stepmania folder.
When you run stepmania (after following the above steps), the songs should automatically load.