Turbotax doesn't allow me to correct one single cost basis in an imported 1099-B nor does it allow me to delete only one imported account

I received the complete picture of the cost basis and whether it is long/short from the 1099-K long after my brokerage sent me the tax documents (a month later). I had imported the Tax documents (1099-DIV, INT, B and MISC) for multiple accounts that we have with this very large brokerage. When TurboTax detected errors, it flagged some of these sales that didn't have the cost basis nor the period of holding, which now the 1099-Ks have. Most likely I declared them Short and cost basis as zero.

 

Now that I want to correct them, Turbo Tax is not allowing me to open up the forms in editable mode. The help next to the form says I should delete the import and reimport them. So, having resigned to this as the only solution, I went to delete the specific account that I had imported. NO!!! Looks like I have to delete the who import (all the accounts) from that brokerage and start over again. 

 

This sounds like a fairly poor all-or-nothing option. Is that right? Or is there another way?

 

Appreciate any suggestions...

 

Thanks in advance.