1. In view of one of your aunties intestate death and due to her name mentioned as one of the beneficiaries in your grandfather's WILL, her specific property mentioned in her father's WILL goes back to the main stream to be distributed equally to all the legal heirs, including the other aunt, who is unmarried and alive. In other words, the entire movable and immovable properties, including the deceased aunt's property ( as specified in her father's WILL ), goes back to the main stock.
2. In case of any deceased legal heir/heirs, their individual share will be further subdivided equally to all such legal heirs.
3. The surviving aunt can't be choosy from the list of properties mentioned in the WILL. She can only bequeath the property specifically listed to her in the WILL and she can't execute the WILL for the entire/other properties.
4. It's advisable to partition both the movable and immovable properties amongst the legal heirs, except the property bequeathed to living aunt.
5. All the legal heirs can enter into a Family Settlement Deed and resolve the issue.
6. Otherwise, let the affected person approach the jurisdictional Civil Court for Partition declaration and separate possession of the property by metes and bounds.