You have to file an amended return, Form 1040X, with the correct Form 1040NR attached. You cannot do this with TurboTax. Download Form 1040X and its instructions from the following links on the IRS web site. You can easily complete the Form 1040X by hand.

Form 1040X: https://www.irs.gov/pub/irs-pdf/f1040x.pdf

Instructions: https://www.irs.gov/pub/irs-pdf/i1040x.pdf

Here is what the IRS instructions for Form 1040X say to do for your situation.

• Enter your name, current address, and social security number
  (SSN) or individual taxpayer identification number (ITIN) on the
  front of Form 1040X.
• Don't enter any other information on page 1. Also, don't
  complete Parts I or II on page 2 of Form 1040X.
• Enter in Part III the reason why you are filing Form 1040X.
• Complete a new Form 1040NR return (see below).
• Across the top of the new or corrected return, write
  "Amended."
• Attach the new Form 1040NR return to the back of Form 1040X.
  

Since you are a student, you should be able to use Sprintax to prepare your Form 1040NR (or 1040NR-EZ) return. TurboTax has a partnership with Sprintax to prepare a 1040NR federal tax return and corresponding state tax return for certain categories of nonresident aliens. Go to the following link for details and to get started.

https://www.sprintax.com/non-resident-alien-tax-1040nr-turbotax.html

IMPORTANT: You have to do this separately for each year. Mail the amended return for each year in a separate envelope. Do not put both years in the same envelope.

An amended return cannot be e-filed. You have to print it and file it by mail. It takes the IRS up to 16 weeks to process an amended return. If you are amending 2016, don't file the amended return until your first return has been accepted and you have received the original refund.