How does one adjust line 7 marked 7d on a 1099-r for the first annual non qualified annuity payment that was paid for with after tax money?

To change your 1099-R in TurboTax, follow these steps:

1. While in your Tax Home,
2. Select Search from the top right side of your screen,
3. Enter 1099-R,
4. Select Jump to 1099-R,
5. Follow the On-Screen Prompts to complete this section, when you get to Box 7, use the drop down menu to select D.  Annuity payments from a non-qualified plan.

Unless the plan calculated the taxable amount in box 2a then you would use the "general rule" for a non-qualified annuity with a after-tax basis if box 2a is blank and box 2b (not determined) is checked.  You do not change the box 7 codes.

See IRS Pub 939.

https://www.irs.gov/pub/irs-pdf/p939.pdf