Q:

How to change column name in SQL Server?

I'm new to SQL Server and I think I need a little help. I'm trying to rename the column heading in ItemDistributedStatus, AssignedTo, AssignedDept to just STATUS, ASSIGNED TO, DEPARTMENT but the AS 'column Name' doesn't take effect on them since I think they already have the AS from the CASE query. 
So I'm just not sure how to do it, already tried enclosing it with () and I'm just getting error.
Here's my query code.
SELECT 
   CASE 
      WHEN ItemDistributedStatus = 0 
        THEN 'Available' 
      WHEN ItemDistributedStatus = 1 
        THEN 'Assigned' 
   END AS ItemDistributedStatus, 
   SerialNum AS 'SERIAL', 
   ModelNum AS 'MODEL', 
   ItemType AS 'TYPE', 
   BrandManufacturer AS 'MANUFACTURER', 
   CASE 
      WHEN AssignedTo IS NULL 
        THEN '-' 
        ELSE AssignedTo 
   END AS AssignedTo, 
   CASE 
      WHEN AssignedDept IS NULL 
        THEN '-' 
        ELSE AssignedDept 
   END AS AssignedDept, 
   DateAssigned AS 'DATE'
FROM    
   TblItemDetails

A:

SELECT 
    CASE When ItemDistributedStatus = 0 
            then 'Available' 
         When ItemDistributedStatus = 1 
            then 'Assigned' END     AS [STATUS] 
        ,SerialNum                  AS [SERIAL] 
        ,ModelNum                   AS [MODEL] 
        ,ItemType                   AS [TYPE] 
        ,BrandManufacturer          AS [MANUFACTURER] 
        ,ISNULL( AssignedTo, '-')   AS [ASSIGNED TO] 
        ,ISNULL( AssignedDept, '-') AS [DEPARTMENT] 
        ,DateAssigned               AS [DATE]

From    TblItemDetails

