How do I add cosmetic character skins to my game? (C#)

I am adding IAP products to my game and want to add some skins for the playable characters. How would I go about replacing the playable characters appearance with that of the skinned ones? (i.e, making my skeleton character into a zombie)

So I guess you would need a reference to your player first:

public GameObject player;

Next you would need a reference to the object to change to so this:

public GameObject skin;

Then you would call a method to change the player to that skin I guess. You could go about it in a lot of different ways. Here is one way I guess.

void ChangeSkin() {
    GameObject newPlayer = Instantiate(skin, player.transform.position, player.transform.rotation);

I know there are much better ways but this is just an idea I quickly came up with.