Calculate Statement Lines unable to modify the total amount. How can I change?

How can I modify the lines in Retail - Open statement. System doesn’t allow me to edit or add new tender amount in Calculated statement line. Note : Cash and Card payment method counting required check box is marked Yes. What should I do to so that I can modify the cash and card values in Calcualte statement in AX 2012 R2 in Retail

Thanks in Advance.

Thanks and Regads,

Himanshu Parekh