The above comment tells you how to ask TurboTax Support to unlock your 2017 return. There's another option if a tax return transcript will suit your purpose. You may be able to immediately download a free return transcript at the IRS website if you qualify to open an IRS account there. Otherwise, to order a transcript to come by postal mail takes 5-10 calendar days.
http://www.irs.gov/Individuals/Get-Transcript
