If you open up the Sidebar (use View-> Sidebar or Ctrl+B) and select the player model you've added, one of the boxes will be labeled equipment. You can select a set of equipment from there (the sets themselves are defined in public/(your mode)/stats/generated/equipment.txt). You can edit appearance like face and hair under the VisualSet box.
Awesome, thanks
A thing though;
After doing this, you need to click "File" -> "Reload Level" in order to see your changes.
