TurboTax has stated that efile does not work for people like our situation (even with the latest software patches). So the only option is to paper file it via US Postal Services. Just printed out as I have indicated above and print out the 1099-R with the method I suggested. I would file both together so IRS knows that the extra amount is for "Excess Income Deferral". The code "8" in box 7 of 1099-R will indicate that this is for 2018 excess 401K contribution. So when you get the real 1099-R next January 2020. You can just ignore that since you already took care of it in 2018 tax return.
Just remember don't try to efile it. It doesn't look like TurboTax will fix it.
Best Luck!
