Itemizing Deductions

I want to go back into my Itemized deductions, but when i do i'm shown the bar graph with my itemized number vs the standard deduction. Underneath it gives me three options: 
Change my deduction
Why would I want to change my deduction?
Explain these deductions 

If i choose 'Change my deduction' will it erase everything I've inputted thus far, or let me edit?