I'm in. I'm 60 (and a little more). I believe it is possible to lose a significant amount of weight at our age. It's also possible to do it with limited ability. I have a spinal cord injury which has resulted in chronic nerve pain and partial paralysis. I can still walk, though with pain so I do pool exercise and work out on a recumbent bicycle. It isn't much but it's more than I could do before I started.
Along with others, I recommend calorie counting, but I'm kind of a nerd so it works for me. I've heard others complain that it's too much work. Regardless of the method, it's got to be for you and no one else. These boards are here for support when you need it and help celebrating your successes.