My father had living trust. My stepsister took im up and had it changed when he was on deathbed. She was only to get house & us remaining assets.

If your father's living trust provided for you or if he had an estate plan prior to this one that provided for you or, if he did not have a prior will or trust, you would be interested as n heir.  In either case, you would have a right to contest the validity of the change to the living trust, if you believe and have evidence that your father was not capable of understanding what he was signing or if he was unduly influenced.  Based on the very small amount of facts you have conveyed, it sounds like both probably existed or occurred. I am happy to discuss this with you further, if you are interested. My number is: (214) 965-9999. Sincerely, Kevin Spencer www.spencerlawpc.com