Form 5329 for withdrawal of excess contribution from traditional IRA

Hello. I made the maximum contribution of $7,000 to an IRA for 2019, but discovered I hadn't enough earned income to take it. I filed an extension, waited until September when I would be 59 1/2, then withdrew the entire amount including the accrued interest. I've been told I need to file Form 5329 and fill out Part III, line 15, "reflecting that the withdrawn contribution is no longer treated as having been contributed." But the instructions don't explain how to do this. Do I put in zero, rather than $7,000? I can't use TurboTax because I have to attach a statement explaining the distribution.