If you're using TurboTax Online, from the Income & Expenses page, EDIT Self-Employment Income & Expenses, and on the next page, click on the Pencil Icon to Edit your Business.
On the next page, under Payments & Identification, you'll see where you can change your EIN.
In TurboTax Desktop, at the Wages & Income page, scroll down to Business Items > Business Income & Expenses and choose Update. On the next page, EDIT your Business.
Continue, and on the screen Enter Employer ID Number, choose Yes, and correct your EIN.