Changing a last will

My family is going through a tough time. My great uncle was hospitalized for a fall. His doctor reports didn’t look good. He had a pacemaker put in.

He has no wife or kids but 4 close nieces and a nephew. His nephew who he was very close with was named his executor.

When he was in the hospital, 2 of the 3 nieces were there a lot. They did a lot for him.

It was after his death that the family found out the 2 nieces changed the executor and his will. The one niece is now the executor and typed out a new will.

In this new will, her son (age 15) gets 4 guns (B.B. gun, rifles) and ammo. One man married to a niece gets 4 guns and ammo. His nephew and former executor gets 4 guns - no ammo.

The new executor is a realtor and in the new will she is to sell his house and car.

The family is outraged that these 2 nieces changed his executor and will without telling anyone. One niece claims that he was insisting on it.

What do you think? Is it right to change a will this way?