Quote Originally Posted by Elfred View Post
You redeem the 3rd anniversary tokens in Diamond shores. Kirby is out there near to one side of the library. Where the infamous turkey was.

The Gumball machines out there near Kirby are where you put the coins in to get your capsule, which you then open.
If you don't want to go to Diamond Shores, you can redeem them in Mirage Isle. Go to the Composition Workbench next to Master Combiner Ogolloro, click on Mirage Isle, then Pet Supplies (because apparently Mirage Capsules are considered pet supplies).