You don't try to change you county residency in the front part of the Ohio program. You claim part year school district (SD) residency in the SD portion of the program
TurboTax (TT) does not automatically prepare an SD return, you
must initiate it. At the screen, in the Ohio
program, titled
"A few things before we wrap up your state taxes"
scroll down to School district taxes.
Or, later
"Your 2016 Ohio Taxes are ready for us to check"
-Click Other situations
-Scroll down to School district taxes.
Quite frankly, at this point, don't bother trying to use TT. You can do the SD form (SD100) by hand easier. The key to not being taxed for the income received while not a resident is simply entering your non resident income on line 22 of SD100.
Form SD100 https://www.tax.ohio.gov/portals/0/forms/school_district_income/2015/SDIT_SD100.pdf
