How do I handle a financial aid gap after changing my major from Biology to Art History in my sophomore year?

I'm a sophomore who just switched my major, and my new degree plan requires fewer credits per semester. My financial aid office says I might lose my full-time status if I drop below 12 units. I've checked the handbook, but I'm not sure how to request a course waiver or find approved electives to keep my grants. Do I need to file a formal appeal to maintain my funding?