I don't know for sure, but I have a feeling that importing the corrected 1099 won't work. I wouldn't even try, because it might cause problems.
Importing 1099 information from a brokerage depends on the brokerage creating a special import file that TurboTax can access. We don't know if the brokerage will even do that for the corrected 1099. Even if they do update the import file, trying to import again might import everything in the consolidated 1099, not just the corrected dividends. That would really make a big mess of your tax return. That's why I recommend that you not even try it. There's no good way to undo an import. If the only change is in the dividends (the 1099-DIV section of the consolidated 1099), making the changes by hand should be simple and only take a minute or two.
