Can I get a copy of my Dad's w2 for a couple of years to see his income reported before my brother became executor of estate?

He made his self joint on all my dads accounts, so we cant tell whats his and whats my dads, just cause he is executor of estate, I thought he did nt have a right to change all my dads accounts, sell and trade his assets, cars, sell his home and rental building, when he had over 170,000.00 in the bank, he didnt ask us, we didnt see the money, he reported 170,000.00 and then six months later sold his home for 110,00 and building for 140,000.00 and when my dad died 3 months after then he only reported 175,000.00 in assets. how do i get access to my dads closed account, and my dad is deceased