Well unless doing something drastic and dangerous, I'm not sure. You can show your grandpa that you still love for being him and not money, well you can alwas try to convince him to not legate any money to your family, if money ruins it that badly. Well, that would be quite a bad option though, if they find out that you're the cause of it, or too ask grandpa telling them that no money will come out for fighting.
Sorry for not being that helpful, I lack experience in this area
>>1.
Good luck!