First of all you need to go after your own dreams. You can't let anybody but yourself tell you what kind of work you would like to do. You won't be truly satisfied with yourself until you go after your dreams.
OK that's step one, now to deal with your parents. Have you ever talked to them about why they want you to become a lawyer? Most parents care deeply for their children and want what they think is best for them. Why do they want you to become a lawyer? Is it the money, status, etc? Of all of these things, I'm sure happiness is pretty high on that list. Maybe they want you to accomplish what they never did. I don't know. Anyways, if you try and talk about why your parents push you to become a lawyer it will be a good start.
One way to convince people to think your way is to make your wants their wants. In your example, if your parents want you to be have money, remind them that law school will give you a huge dept from student loans. If it is social status, this could be a bit tricky as your value system could differ greatly. Perhaps remind them how lawyers can have a bad reputation for being dishonest. By being a fashion stylist/journalist you can help the world be informed on how to look their best. Having good looks boosts one's confidence and automatically raise one's social status.
Where I'm going with this is people are really not going to listen to what you want because they are more interested in what they want. If you can somehow find out why your parents want you to become a lawyer and convince them that they can accomplish their wants by you becoming a fashion stylist/journalist then you have the support of your family.
If all else fails, I'm truly sorry and will support you with others on this site. Follow the advise that the other people gave above and go after your dream. You may need to be broken down to be stronger, but your parents also need to be broken down by learning they can't have full control of their child's life anymore.
Now I don't know how far you were in the corporate world, nor do I know what your parents do for a living, but I truly hope this helps.