Delete current MSSQLLocalDB instance then create a new one.
C:\>sqllocaldb stop MSSQLLocalDB
LocalDB instance "MSSQLLocalDB" stopped.
C:\>sqllocaldb delete MSSQLLocalDB
LocalDB instance "MSSQLLocalDB" deleted.
C:\>sqllocaldb create MSSQLLocalDB
LocalDB instance "MSSQLLocalDB" created with version 13.0.1601.5.
C:\>sqllocaldb start MSSQLLocalDB
LocalDB instance "MSSQLLocalDB" started.