Please clarify - what is it that you are trying to edit? If you are going to enter more deductions then keep doing that. As you add deductions your itemized deductions may become greater than your standard deduction. At that point the system will automatically switch to using your itemized deductions. In the meantime the standard is better for you.
I originally entered my medical deductions however forgot some receipts. I now need to go back into add more medical deductions. When I click edit for that section is when I get the page saying turbo tax has my medical expenses.