I married 1957 divorced in Feb 1968 we had 3 girls he passed away and never married had two children but did not live with there mom. This happened in Mexico.
What can the girls do to get what belongs to them

How long ago did he die?

Good luck trying... its going to be a fight (meaning lawyers and legal fees) unless he left them something in his will... there isn't an entitlement to inheritance in most of the USA... meaning a parent can give EVERYTHING to anyone they want when they die... and if there is probate... the court might suck up whatever value is left in the estate if there isn't much.

There is no such thing as 'what belongs to them' because as smoothy said, he could have left everything he had to someone totally unrelated, or a church, or anything. Plus even though he didn't re-marry, his other children can claim a share if there was no will. That would mean 5 of you. Do you know that he had an estate worth finding out about?

Please clarify a few things:

1. Was he a resident and/or citizen of Mexico when he passed? If he was a resident of the US, what state?
2. Do you know whether he had a will? If so, do you know what it says?