How do I fix chin

Breathe through nose.

Grow a decent beard to hide it.

Get a chin implant. It won't hurt, jsut make sure u got money

Sadly,its too late for him.
If your parents have not taught you to shut your damn mouth,you will end up like that.
Sorry OP,the only option I see is to go to surgery.

youtube.com/watch?v=vhPZsaA0SL4

I don't know if mewing would be effective but no harm in trying it. keep your tongue on the roof of your mouth

Nah his chin projects enough, what the guy in OP's pic really needs is a sliding genioplasty to add height to his chin.

1. Lose weight
2. Braces

If those fail consider surgery.

Bottom pic is the result of a double jaw bimax operation and genioplasty + cutting bodyfat. It'll take you about two years and $30,000. Get it done op.

why does he need double jaw. cant he get jaw surgery? or better yet cant he just get a chin implant or somethin?

grow a beard

1) see an orthodontist. they might be able to fix your overbite
2) lose weight. this will help increase jaw definiton
3) cosmetic surgery. if your genetics/environment failed you, there's always anothery way out in today's world