Will execution of immovable property

My Mother-in-law made a will, which is properly registered in the court.

She has appointed me as her will Executor.

She own three houses jointly with her son, who expired in 2009. In her will she has given her share (50%) in the three houses to her two daughters (25-25%). Her Sons share (50%) will go to her daughter-in-law. 

Mother-in-law expired recently.

Please guide me how to proceed to execute this will?