My question involves business law in the state of: NY

Long story short:
A and B are 2 friends going into business together. They form an LLC. 1.5 years later A says he wants out, and they change the paperwork. One problem--a car is under A's brother and the insurance is under A. B offers to buy out the car right away (bank still owes it). B says he'd rather sell it for a little more than he owes, and just pocket the difference. All he needs is $800 make it look proper. B gives him $1k cash and access to checking account for $800.

The next day B finds out his bank account is overdrafted b/c A took out all of the money and more. He asks what's going on and A says, "this car is never going to sell for $x (amt he said he'll sell it for), you should have known better. You left this all on me. It's all your fault."

B offers to buy it out again, minus the money taken from the account and under conditions that A surrenders excel speadsheets, terms of service papers, some tools, nd removes himself from insurance. Then he will give him the check the same second the actual owner (A's brother) buys it out and signs over the title. A also has about $6k worth of computer parts stored at his house, but B was willing to leave it so A could sell it if he needed the money.

Sounds completely fair, but A says no way. In fact, he says he will keep all the parts or sell to B for $1,500 (A never paid for them from his own pocket), and he will also sell the paperwork and domains for another $3k.

Now this is getting beyond ridiculous. What is the best way to go about this? B wants his paperwork and parts, and he shouldn't have to buy it from A.