Most Helpful Guy
You should not help him with his business, at all. He moved on from you, you need to do the same. Otherwise it will just get harder and harder for you to move on, and you will eventually get more and more upset if he starts dating other people.
Helping him is just letting him take advantage of your emotional attachment. It is very detrimental for your long-term emotional health.
Most Helpful Girl
He is using you, really.
Not only using your skills and caring persona but also your emotions.
That's messed up.
He will not love you cause you're helping him.
You're just a tool.
If you stay and help him, not only will you make yourself look bad but you'll be disrespecting yourself.
You deserve better!
Let his new gf do it!
You have better things to do with your life than stick around doing paper work for your useless ex while he has fun girls.
He's not your problem anymore!
Stop it all! Don't contact him! Put your foot down and say "no"! Tell him off if you it makes you feel better.
It's time to start a new chapter in your life!