Currently you cannot do this Jessica - the options you have are
1) Delete the Design and Recreate it
Is this just because you gave it a Bad Name or had a Typo in the Name?
You can change the name of a Design at the Controller level in the Sync Folder but that wont change it in the Source BC-HCE Project so I doubt that helps you at all. By changing the name this would effectively require a Re Sync to all your controllers for the Design, so it would not save a lot of Sync Time just Renaming it - it would maybe save you a few seconds in BC-HCE.
Let me know
Alan