I and my wife have F1 Visas. We are attending at different English Program Schools. Now, I need to change my Visa status from F1 to F2 to be an attendant with my wife. Because, I want to stay home for the following reasons:
1-To take care for my children.
2-I have my own business in my home country (Saudi Arabia), So, I want to run my business remotely.
3-My wife doesn’t have a driver license, so my family needs me all time.

What is the best and fastest way?
1-Changing my Visa status from F1 to F2 within the United States. How much the lawyer cost?
2-Going home to change my Visa status in Saudi Arabia then coming back to the United States with F2 Visa.
Thanks.