DECLARE @cols AS NVARCHAR(MAX),
@query  AS NVARCHAR(MAX)

select @cols = STUFF((SELECT TOP 7 CAST(',' + QUOTENAME(c.name) AS NVARCHAR(50))
                from tempdb.sys.columns c where object_id =
                object_id('tempdb..#MyTempTable')
                AND c.name NOT IN ('description')
        FOR XML PATH(''), TYPE
        ).value('.', 'NVARCHAR(MAX)')
    ,1,1,'')

SET @query = 'SELECT * FROM #MyTempTable
          UNPIVOT (
            Qty FOR Customer_Name IN (' + @cols + ')
          ) unpvt
          WHERE [description] NOT IN (''Grand Total'') ORDER BY [Customer_Name] ASC'

exec sp_executesql @query;