To perform a Model Change, you will first need to purchase a Scroll of Model Change from the Vote or Donate NPC.
When double clicking the scroll, a new window will pop up.
On the left, put the item you want to keep with the model, on the right, put the item you want to use the model of.
Items being consumed by putting them in the wrong slot will not be refunded.
Every item can only be modelchanged onice. To remove the model from an already modelchanged, you will have to purchase a Scroll of Modelchange Reversion from the Fashion NPC.
You can also decide to purchase a Scroll of Modelchange Recovery, which will restore the original model item to your inventory, but is far more expensive.