You can download and install the 2016 version of TurboTax. You will have to enter the original return first, and then go through the process of amending the IT-201. To download TurboTax for 2016 please click this link: TurboTax 2016 Products
For instructions on amending a return, please see this TurboTax Help article: How to amend (change or correct) a return you already filed
If you want to do the amended return by hand, you could get the forms from the New York website: NY 2016 Forms
[NOTE: You will not be able to file the amended return electronically -- you will have to print and mail it in.