My father disinherited me and my brother in his will, naming us and saying that he had otherwise provided for us in his lifetime. This was false.

He sexually molested both my brother and I. I have 2 sisters who committed suicide in their 20''s. Psych literature supports the theory that they were also sexually abused as children and it is very common for girls of sexual abuse to commit suicide. I have much younger siblings who stand to inherit. Is there any ground that my brother and I can contest this will. I would also like to clear my dead sisters'' names in so far as they weren''t ''crazy'' but were damaged by my father. The surrogate hearing is in New York on April 25th 2012.