I am very sorry that you have to deal with this horrible situation!
Since the value of all assets is less than $100,000, you can avail yourself of California's small estate affidavit procedure. This is a non-court procedure that allows you to request the financial institution to transfer the asset by providing a certified copy of the death certificate along with an affidavit following the requirements of California Probate Code Section 13100 (and et. seq.).
Kansas has a similar procedure for estates of less than $40,000.
Forms should be available online. They are usually very basic and should not be difficult for you to complete yourself and take to your bank.
If you are not sure about what to do, seek counsel with a few probate attorneys in your area. Many offer a initial consultation at no charge.