How can I help getting my father to probate my aunt's Will as I feel that he didn't distribute everything according to her wishes?

I am so sorry for your loss and for the problems that have occurred.  So let me understand: your Aunt's possessions have already been distributed?  But your Father did not probate the Will?  ANd he has the Will, correct?  Every state has a way to force the party that is named as the personal representative in the Will - the executor - to probate the Will.  It is probably called something like a motion to compel probate.  Once you bring te motion in probate court you are going to have to challenge your Father's distribution or his appointment as executor based on his improper distribution as you claim.  Good luck to you.