My father recently passed without updating his will since the early 80's. All the money went to my stepmother. She chose to give me a small amount, and I have no doubt the when she passes the whole of the estate will go to her two children.

My stepbrothers were never adopted and have a close relationship with their father.

I also do not know what was stated in my fathers will, and if I have a right to see it.

The estate is much larger than the amount of money my stepmother gave me. My real mother died in the 1960's and has no part in this.

I truly doubt it was my fathers intention for all to go to the stepchildren. I had a close relationship with him.

When my stepmother passes is there something I can do to make this will the way my father would have wanted it? He became very sick in his final years and didn't understand what was going on, and God knows she did nothing to change that.

What rights will I have when the time comes?

Your father's will is done - everything went to his current wife. What matters when she dies is what she writes in her will.

"When my stepmother passes is there something I can do to make this will the way my father would have wanted it?"
Her will is totally independent of his.

If you think she will leave everything to her children, there is nothing you can do. It happens all the time. A few children do sue, but it is very expensive, and there's no way to know if you would win a dime, even after thousands of dollars of legal fees. And you would need evidence that your father was incompetent since the last time he wrote his will. Undue influence by his new wife probably won't have a chance in court.

is there something I can do to make this will the way my father would have wanted it?

The problem here is there is nothing to prove the way your father wanted it. If in his will, he chose to leave everything to his wife, then she gets everything. It is now hers to do what she wants with it. You are now out of the picture. If you want to contest anything you should contest the will that left everything to the step mother. Once that will is probated and complete, then it is her money and assets.

If she chooses to leave everything to her natural children its her choice. If she dies without a will, you get nothing since she never adopted you. That he didn't adopt her children has nothing to do with this.

I'm sorry, but that's the way it goes.