My son will soon be turning 18 (june) how do I get the child support reduced? Is it automatic or is there forms I need to fill out and which ones?

What does your support order say about when support ends? Is your son still in school? What level? How is support collected?

If your paying through the state then you need to let them know ASAP. That way they can process the paperwork needed to end the support when your child graduates. Don't wait as it can take a long time.

18 or 19 and has graduated high school. Both will happen in June this year. They are currently garnishing my wages now

Is there a number I can call or is it done through filing papers through the state

You can find the number here for your local office.

California Department of Child Support Services > Home

Contact the agency that Califdad linked to and find out what needs to be filed. Also talk to your payroll department and ask what they need to end the garnishment. They may be able to do so based on the support order.