We can outline what a person needs to do to become happier and healthier but we can't force them to do the stuff.  I gifted someone with The Secret's Daily Teachings Book for Christmas and they used it for a few days before reverting back to talking negative all of the time and constant complaining.

What you can do for your father is send him love and happiness through meditation.  You can also display the goodness in life by your actions.  Do thoughtful and fun things for and with him. Tell him to have a nice day,  catch a movie together,  take up a hobby together.

I hope this helps.