WHO can help me to overcome presumption of paternity in Pa law?

I have DNA test that says I am 99.91% the father and no outher man can be the father But I cant overcome a 200 year old law of presumption so I can see my little girl. I need any help out there and will respond to all who offer. This is injust and I cant see how it can be allowed in Pa law. I have the DNA test the outher guy had a vasectomy 3 years prior and she was seperated and it can be proven. What can be done?