Before you can find a remedy, you need to find the cause. Just because your hands shake when you do fine work doesn't necessaryily mean it's a "disease."
MY hands shake sometimes for a number of reasons. My age, I drink a lot of coffee, I'm on medications that can cause tremors and because I use the computer for my job and all my personal correspondence. It's been YEARS since I've done more than sign my name, so now, when I try to actually write something, it looks like a drunken scrawl.
But...........I am NOT a doctor and I would advise you, AND your father, to get a professionals diagnosis.
Peace
Greenlydia