To take it apart is very similar to the 92FS.
The gun must be in the de-cock position or it won't dissemble. Simply push down on that little lock button and swing the little lever forward. The key is NOT required to take the gun apart. I put the key in the pictures to show how you can lock it a few pics below*.
Once the slide is off, simply remove the spring and barrel. Done.
To put it back together, just put the slide back together, put the slide on the handle and pull it back. It will automatically re-lock the slide similar to a Glok.
*To completely lock the system, use the key to push in the button and turn it 90 deg CCW. Once locked, the slide will not move and the trigger cannot be pulled. Simply reverse the process to unlock it.
You mentioned the 92FS. Here is a side by side comparison of the two. Steyr is definitely smaller. It's got about a 4" barrel.
I handled a couple at shows, but bought it online witout having a chance to fire one.
Hope this helps.