David,

Off-topic for this thread, but assuming that OldCol is your IDENTITY column:

ALTER TABLE YourTable

ADD NewCol INT NULL

GO

UPDATE YourTable

SET NewCol = OldCol

GO

ALTER TABLE YourTable

ALTER COLUMN NewCol INT NOT NULL

GO

ALTER TABLE YourTable

DROP COLUMN OldCol

GO

EXEC sp_rename 'YourTable.NewCol', 'OldCol'

GO