1) Spray yard with "round-up" then after 10+ days & use rake to break surface of soil Apply seed at 6-10 pounds per 1000 square feet (check with local garden cewnter for low maintance varitey for your area) rake soil to cover seed lightly..... keep area watered (damp) 3-4 times a day till graas is up then once a day....mow after grass after reachs 3-4 inches (mow level to 2 inches)

Unless your garden soil is quite sandy(unlikely in California) the removing of the dead weeds with a rake, plus loosing the soil enough for seeds to get a start is going to be more work than you may think. I would look into hiring a local handy man to rototil your yard. Agree on the cost before starting. Al