The story again:
My father married 1st wife whom died (I think during the civil war) and married a 2nd one who is still living. Now my father is dead (1993). The 1st son of my father (age 62) from the 1st wife wants my mother (the 2nd wife) to pack out of the house where she lived with my father till his death in Enugu state after 20 years of my father’s death. And for those 20 years my mother has been collecting rent and managing the house where she lived with my father till his death with no question from anybody on how she spends it. We have 2 properties in Enugu state which are not of the same size or in value. Where my mother is living now is a full plot of land the other is like half plot of land. The other property out comes where being given to my step brother until we, the children of the 2nd wife grew up for university degree. Then the property outcome was then used to sponsor us.
The 1st son (I’m the 1st son of my mother the 2nd wife) now wants us to share our father’s properties. Stating that the one where my mother is living now which is also the place she lived with our father till his death is the one he requires. She is required by him to move to second property (smaller in size and value). He has also written papers for my mother to sign in which it state he is now the owner of where my mother is living and my mother the other property. We are from Anambra State. 1st son has already taken the house in village as the Obi (Igbo tradition in Anambra state Nigeria) due we are still living in it but he built another house in the compound.
My questions
1. Is he right to send my mother of the house where she lived with the husband?
2. How is property sharing done in the case a deceased husband where there are two wives, 1st dead and 2nd still living?
3. What will be the court verdict if we are to go to court? Will it be to sell both properties and share money equally?
4. Your advice on the case please.
Note:
My mother was wedded wife of my father.
Both property documents have been changed to both name (My mother and my step brother and my mother’s name stated 1st) as the administrators. Ie. Letter of administration.
My mother is having the letter of administration of the house she is living in now. The letter for the other is with my step brother.

Hmmm this is a dificult case I must say.
Be strong, courageous and prayerful and everything will turn out fine.
I advice you to go and meet your Lawyer, forreal.
Some ignorant nairalanders may give you sick and silly advice.

Did he die intestate ie without a will?

This problem exists because your father did not write a will. All parents should be encouraged to do so. What was your father's instructions before he died? Your mother should answer this question. Usually in most cultures, the first male child is the administrator of the family estate if a man died inestate. However, if a family is united, a sharing formula can be adopted after a series of meetings. Finally, no property is worth dying for. If you work hard, you can get one.