Corrected Composite 1099

Schwab sent a corrected 1099 which has DIV and B info. The 1099 has 312 pages to it! Since it's a consolidated 1099, I'd have to import both DIV & B. What's the best way to update? I see there is an option off file in main menu for import removal that I can delete the DIV and B parts of that 1099, that the best way? Then import the new 1099 via which method?