I am sole trustee for my moms trust since my brother passed 6 days before my mom. I don't want to give my brother 1/3. Any suggestions?

I don't want to give my eldest brother 1\3 he didn't contact mom for three months never hardly came to see her does anyone know what would happen my mom wrote on piece of paper that she wanted him to receive 5% but my lawyer said he couldn't change it.  He has said horrible things about me. I was at nh everyday sometimes twice while he did nothing even brother who past lived 2 1/2 hours away and worked full time job saw her more than him. Any suggestions?