Timothy, I am not an FFL and am inside the PRC, so have not had to do this, but it is my understanding that an out-of-state FFL just goes to the CA DOJ web site (accessible through ca.gov) and gets a code number assigned to your FFL so that an in-state FFL can receive guns from you to transfer to CA residents. If you are NOT an FFL, you don't need to do anything except ship directly to an FFL.

There was a detailed thread on the procedure a couple of months ago. I'll see if I can find it later.