Roth Recharacterization for 2017 where and how to input manually in 2018 Turbotax?

[Luk]

I backdoored a decent amount ($25k) into Roth from Traditional IRA in 2017.  Now in 2018 I've decided to re-characterize the entire sum $25k back into Traditional.  Turbotax downloaded my 2017 1099-R from Fidelity showing the entire sum ($25k) as an ordinary taxable distribution.  Now, what process do I go through to capture the re-characterization of this $25k into Turbotax so it can calculate my Federal Taxes excluding the $25k distribution? Please help?    

[PaulaM]

See dmertz's answer below for reference.

Recharacterization of IRA to Roth Conversion