Deleting duplicates in SQL Server before adding a Unique Index

Quick reference on how to remove only the duplicate rows when attempting to add a unique index:

WITH custom AS (
SELECT [projectId], [zoneId], [type], [name], RN = ROW_NUMBER() OVER (PARTITION BY [projectId], [zoneId], [type], [name] ORDER BY [projectId])
  FROM [mydata].[dbo].[Properties]
)
DELETE FROM custom WHERE RN > 1