Credits and deductions

If you are using TurboTax Online- you will first go to "My personal tax profile" Make sure that you didn't say "Yes" that you had charitable donations- If yes, click on no. (You will click on Edit to update)

Then continue, you will then go to "Deductions" and you will click on "Delete beside the donation you had entered. 

The next page will ask If you are sure you would like this deleted, you will say "YES".