My mother passed away may 2011,she and my step father had there att come over to make me trustee .we had signed all pappers,,its been 1 year 2 months,

i have a brother and sister inlaw that came outa know where and started helping my step father alot,but they dont care for him and have him convinced that im a lier and such,,i have done nothing and my step father emailed me to inform me that he will be changing the trust acc to my long lost brother and his wife who where never there for my mom even up to the day she passed away,,what can i do if anything?,,i live in fla,