Change clustered index without dropping the primary key
Just drop the existing clustered index, then create a new one on the ID column.

DROP INDEX [Created] ON dbo.Realty;
GO

CREATE UNIQUE CLUSTERED INDEX CX_Realty ON dbo.Realty (ID);
GO


Of course, you'll want to do this during a maintenance window so you don't cause too much blocking.  If you have Enterprise Edition you can do the CREATE INDEX operation online by adding WITH (ONLINE=ON) to the statement.