There is a person who puchased merchandizes from me and he did not pay me as promissed. I sue him in Small Claims court and got a judgement against him. He still did not pay me. What are the procedures to levy his bank account in CA? Can I do it myself? If not, what are the estimate cost if I have to hire an attorney to do it?

You find out where he banks and the account number. Then you go back to the court that issued the judgment and ask for a writ of execution. Then have it served on the bank.