I received a 1099-R in 2018 showing excess contribution and taxable earnings in 2017 (code J P). How do I amend my 2017 return to reflect these earnings?

I found where to amend the 2017 return in TurboTax, but I'm not sure if I should enter the 2018 1099-R in the 2017 amended return. Line 2a shows a taxable amount. Can I enter just this amount without entering the entire 1099-R for a different year?