Changing books after drop/add

<p>I used the drop/add today and got a class that I wanted. However, I had already ordered my books for the class I dropped (I am to pick up my books on monday). How do I change my order so that I can remove the books from my old class, and add the books from my new class?</p>

<p>Thanks</p>

<p>I think there’s a certain time period where you can return books for a full refund if you drop the class. Then just buy the one you need.</p>