My grandmother ped away 2 years ago, she left a will leaving the house to my father?

We have been living in the house for almost the full 2 years, recently my father ped, he had no will. My stepmother has a copy of my grandmothers will, she will not give me a copy for some reason. Can you please tell me the steps I need to take to get a copy of my grandmothers will, My stepmother is not returning my calls. I only want fairness and feel like something is wrong with this picture, can you please tell me the steps I need to take to get a copy of the will, "it was done by a lawyer", the problem is I don't know who. Thanks in advance.