MS-SQL “UPDATE”

How to use Update in MS SQL Server:

UPDATE 
[dbo].[TEST_Scen_Years]
SET 
[dbo].[TEST_Scen_Years].[TAE] = [dbo].[FinalHistYear_TPD_Train].[TrnCnt]
FROM
[dbo].[TEST_Scen_Years] 
INNER JOIN 
[dbo].[FinalHistYear_TPD_Train] 
ON 
([dbo].[TEST_Scen_Years].[Scenario_Year] = [dbo].[FinalHistYear_TPD_Train].[Year]) 
AND 
([dbo].[TEST_Scen_Years].[Subdiv_Part] = [dbo].[FinalHistYear_TPD_Train].[Subdiv_part])
WHERE ((([dbo].[FinalHistYear_TPD_Train].[Train_Code])='A') AND (([dbo].[FinalHistYear_TPD_Train].[TrnCnt])>0));