How to Update Using Two @Temp tables in sql

Question

I have two temp tables called @Temp and @RegTemp

 

select * from @Temp t1

inner join

@RegTem t2 on t1.ID= t2.ID

and t1.FinancialMonth=t2.CMonth

order by FinancialMonth, AccOrder,AccLevel 

 

Here I have combined those two tables and now I wanna do this update using those two tables how can I do that

 

 

I know this is wrong. Please give any solution to do this

 

Thanks