I can feel for your friend. Over the 10 years after I graduated from college I gained over 100 pounds and was probably about 290 pounds at my max. I've taken my time and lost about 45 pounds in the past 18 months, which is slow, but I have gained an immense amount of health and strength because I'm not focused on just losing weight - but on being healthy and if it takes me 3-4 years I am OK with that.
Throughout my life, I ALWAYS thought I hated vegetables. The fact is, while I would never tell her this, my mom was a really, really horrendous cook. She murders everything and makes it inedible. Because of this, I stuck to lots of poor choices. I'm still not a "veggie" person, but I eat baby spinach, broccoli, asparagus, green beans, and probably some others I forgot about.
I'm still a picky eater, and the poor choices always seem so easy and tasty.
One of the things I've done lately is to adopt a simple approach that allows me to be "off" almost every day at some point. I eat chicken and egg whites with 1 whole egg in the morning, broccoli and chicken about 3 hours later, spinach and chicken 3 hours after that and 2 plain Greek yogurts with splenda after that. My final meal at night is just a normal dinner with my gf. Sometimes it's another chicken meal, sometimes it's a hamburger, sometimes it's Chinese, whatever. I try to make that last meal a chicken or other healthy meal at least 5 nights a week, and ideally something moderate the other 2 nights, limiting a really bad meal to 1 night/week or less.
There isn't a lot of variety there, but it works and is easy and requires very little and leaves plenty of room for flexibility.
I am not perfect by any means, and it could be better, but I'm also picky and it works for me.
Also, you have stumbled across some good points for change. Anthony Robbins (laugh all you like) makes some good points about changing people.
It is not important HOW you will do it, but it is important WHY you will do it. If your friend has a strong enough reason to do something, he will find a way. You should spend some time helping him solidify the WHY of what he is doing. What does he want? Does he like not being able to climb a flight of stairs? Does he like not fitting in the movie theater seats? Ask him questions along those lines to really show him how much pain his current habits are causing him. Obviously you are doing this in a caring way, not a mean way.
What will happen if he does not change? To me this is always something people miss with change - they don't think about what will happen if they DON'T change.