The 2019 excess contribution is resolved by making a regular distribution of $6,000. The only thing you have to do for this with regard to any Schwab form is fill out a form requesting a regular distribution of exactly $6,000, although hopefully Schwab would be competent enough to do this even if you request it as a distribution of an excess 2019 contribution. With regard to the correction of the 2019 excess contribution, Schwab must distribute exactly $6,000 as a regular, code J distribuion. There must be no adjustment for investment gain or loss.
I don't think I can just take $6K out of my Roth.
This is indeed exactly what you must do with regard to the 2019 excess. Adjusting for gain or loss is mutually exclusive with paying the 6% penalty on the 2019 excess which you must do on your 2019 and 2020 tax returns.
