1. Press the up arrow button on your keyboard to change the outfits (some cannot be changed). 2. Press the space button to wear the clothes and accessories. (If your mouse pointer touches the outfit you're wearing, it will come off.) 3. Press the "b" button to go back to the start. There are other instructions on the pages. I will upgrade it more later on.
Credits to @With_Lumine for sending me the images.
