Of course you can do that. Nothing would force or require you to use TurboTax to amend if you do not want to. Just get the 1040X from the IRS site and prepare it on your own, then sign, date, and mail it in.
https://www.irs.gov/pub/irs-pdf/f1040x.pdf
https://www.irs.gov/pub/irs-pdf/i1040x.pdf
Do not expect quick results from amending. It can take four months or more for the IRS to process an amended return.
You can watch for information here:
https://www.irs.gov/Filing/Individuals/Amended-Returns-(Form-1040-X)/Wheres-My-Amended-Return-1
**Disclaimer: Every effort has been made to offer the most correct information possible. The poster disclaims any legal responsibility for the accuracy of the information that is contained in this post.**