I am 66, I had my Right Hip replaced at the Mayo 5 years ago, before the surgery I was miserable, couldn't walk! I was overweight, I made sure prior to the planned surgery, to loose some substantial weight, so that after surgery my replaced hip will not suffer like my old hip from carrying all that weight.
The surgery itself and the quick recovery, was much easier than I had imagined. Walking was the only therapy I needed post surgery.
Pick a good Surgeon with plenty experience, and go for it.
Good Luck! P.S. the weight loss helped with not needing surgery on the other hip !