Setting up a special needs trust in California can be a complex process and it's often a good idea to consult with an attorney who specializes in special needs trusts and estate planning. However, here is a general overview of the steps you can follow:

1. Choose a Trustee: The first step in setting up a special needs trust is to choose a trustworthy individual or organization to serve as the trustee. This person or entity will be responsible for managing the trust and using the funds in it to pay for the beneficiary's needs.

2. Draft the Trust Agreement: Next, you'll need to draft the trust agreement. This document outlines the terms of the trust, including the purpose of the trust, how the trustee will manage it, and how the funds will be used to benefit the beneficiary.

3. Fund the Trust: Once the trust agreement has been drafted, you'll need to transfer assets into the trust. This can be done through a variety of means, including transferring ownership of property or stocks, making a direct deposit, or through the distribution of inheritance.

4. Obtain any Necessary Approvals: Depending on the type of special needs trust you set up, you may need to obtain approval from the court or from a government agency.

5. Register the Trust: Finally, you'll need to register the trust with the state of California. This typically involves filing the trust agreement and any necessary approvals with the appropriate government agency.

It's important to note that special needs trusts are complex and subject to a number of rules and regulations. Before setting up a special needs trust, it's important to consult with an attorney who specializes in special needs trusts and estate planning to ensure that the trust is set up properly and meets all legal requirements.