I want to amend my taxes - federal and California tax, but when I start to amend, it begins with a $xxx due for California tax and $0 for federal, I have paid everything

I made few changes a month back and then didn't do anything, later now I started back again for amendment, it thinks I didn't pay my original due amount. My original due amount was same as $xxx. How should I set it to 0 and make my amendment