Grandfather will causing troble ?

So my papa passed away in December. My whole life he gave my parents $2000 a month to make mine and my brothers life better. So when he passed away my family has been be hurting for money. So there are two wills one made in 2008 says me an my bro get everything($100,000 & house worth about $250,000) yet he had alzheimers and left my dad his only son nothing. Yet in the next will made in the last months of his live my dad got it all. Which is what me and my brother want. Yet the executor of the will hates my dad and is going to give it all to me and bro. Yet he is not doing his job to the fullest and he is almost 80. Could we go to court or anything?