It's very simple to use a code on Yoox. Click "Show coupon code", copy the code and use it when necessary.
This is how:
1. Go to yoox.com.
2. Search for your item and click on it.
3. On the next page, check your item details, pick a color and add your quantity.
4. Click on "Add to shopping". When the pop up window appears click on "Proceed to purchase" if you are done shopping.
5. On the new page, fill in your details or wrap the item as a gift if you wish.
Under the heading "Payment options", there is a field titled "Yoox code", type the code and click on "Apply".
You may choose to check out with your pay pal account or directly place your order from the website.