Within the Vietnamese culture, divorce can be a difficult topic. However, if you are getting a divorce in California, you will have to tell others what is happening at some point. Being proactive about it and telling them before they find out some other way can help make the news easier to accept and reduce any misunderstandings.
According to Psychology Today, you should confront the situation directly and tell your family in specific terms that you are divorcing and why. Be clear and concise. You do not have to explain yourself. If you approach this as if you are explaining why, then that is how others will approach it. Instead, just state the facts. Keep it to the point and do not make excuses. This will make it less likely for them to question your decision or bring up objections.
You also need to explain that you need support. However, you should outline how they can offer that support. Some people may try to smother you, which may not be what you need. If you just want to be left alone, then tell them that. Let them know it is fine to call and check on you once in a while, but it is not okay to stop by your home unannounced. This sets boundaries.
Finally, keep them updated. The chances are good that your family is invested in your marriage. They probably have a relationship with your spouse. They care about both of you. They will want to know what is happening. So, make sure to check in with them often about what is going on. This information is not legal advice and is for education only.