Legal Question in Wills and Trusts in California

If it's real property, you can sign a quitclaim- this is often done when one spouse's separate property is financed.

To add to Ms. Cusack's reponse, If the property involved is personal property rather than real property, then a written agreement or statement should state that you have no interest and/or you waive any interest that you may have otherwise had in the personal property involved. For clarity sake, the agreement should specifically list all the property involved. For example, if it applies to your situation, name the bank or investment account that's involved.