Unless you have reason to believe that the taxable amount shown in box 2a is incorrect, you should probably just indicate that that amount in box 2a is the correct taxable amount and should not use the Simplified Method. If no made no after-tax contributions to the plan, the entire distribution is taxable. Many TurboTax users end up reporting an incorrect taxable amount by using the Simplified Method when they have no need to and they do not understand the information that TurboTax asks for when using the Simplified Method.
