Notwithstanding this question is old, the answer didn’t help me so I want to share how I solved it for my self.
On Server Explorer, find your ASPNet DB. Then open it using SQL Server Object Explorer.
Then go and hit Schema Compare option
Then on the the Schema Compare window for the Target database, select the SQL Server data base you want the ASPNet DB to integrate to. Then hit Compare button
Deselect all Delete actions for the target database, and leave selected all Add actions for the ASPNet DB, then hit Update button.
Finally, update your connection string so it points to your SQL Server DB