I'm just wondering, but what if you already have your WIP on here and you want to do NaNoWriMo on that story? Could you get the NaNoWriMo-thing to work on that without having to delete it and re-upload it?
Go to the "Find Your Writing Buddies" society, and you will see a "NaNoWriMo 2016 WIP" thread i just created. Post your story or story ID there, and Penana will transfer it for you as soon as possible:)