Then after say you want to equip wonderfuls and then choose the tool you want to put it on (for your own ones you can only equip 1, but with Gannon's you can put on as many as you want. They cost about 3000G in Gannon's shop list.)
Then tap the wonderful and say yes to put it on.
That's all i had.
Hope i helped a teeny bit at least! :P
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as soon as you win a competition, and get a wonderful, a little boy named Charlie comes up to you and tells you that you can talk to him to equip wonderfuls. if he doesn't come up to you, then go to Chen's store and he should be right beside Chen behind the counter.