1099 Div

I had accounts with TD Ameritrade and they were transferred to Charles Schwab. The Charles Schwab statement includes the dividends from TD Ameritrade plus two months' worth when it was transferred to Charles Schwab. I downloaded both 1099 forms but now it shows double my dividend amount. How do I change the amounts to the difference between the time TD Ameritrade had it and Charles Schwab had it?