Simple, he writes you a check or pays you in cash, just like he would to any other vendor or outside contractor.

Annually, if the amount is more than $600 (which I'm sure it is), he has to file a 1099 at the end of the year for tax reasons when he does the business taxes. You file your own taxes with that 1099 copy he gives.

Not really anything he has to do on his part, until tax season comes.