Black MacBook Top Case Being Replaced - AppleCare Question

Have a black MacBook and have a crack in the top case by the palm rest. Made an appointment (in store) for a repair. Tech Apple Genius told me that it would be covered under my Apple car but am wondering, since I upgraded the hard drive do I have to put the original harddrive back in? Will they not do a warentee repair with a replacement drive? ANy help would be appreciated. Thanks.

you can change the hard drive without voiding the warranty!

Thank You!

Thanks for the response!