Just in case anyone is still seeking the answer, here's how I did it:
1) while in forms view, select (from the top menu) <Forms> <Open Form>
2) For California, select <Estimated Tax Worksheet>
3) then in <Part II> you'll want to check the box next to the option you're interested in - e.g. check the box next to # 2d, 2e, etc. which will make the 'corresponding 'amount to apply' field editable. From here, you can enter the amount to be applied and any amount still to be refunded will be calculated.
Definitely not as easy to do as in previous years, but at least it's still possible...
