I'm Amending 2016 tax return. I filled out the Column A original amount. 

When I review the 1040X on the original amount for line 2 itemized deductions or standard deduction shows 21,501 which is the original itemized deduction showed on the original return, however, column C (corrected amount) shows 12,600 which is the standard deduction and in column B the net change of 8,901. How do I change this to show the correct itemized deduction in column C line 2?

How do I correct this? please help, thank you!