How do I amend my 2016 taxes if I did not use TurboTax in 2016?

After using turbotax for 2017 I realized I should have used itemized instead of a standard deduction for 2016. The accountant I used the last few years has been taking standard deduction when I could have used itemized based on having a home etc. I don't want to go back to that accountant for obvious reasons and prefer to use TurboTax.