What must salzman do in order to achieve his goals? ("the magic barrel") he had to rig things so leo rejects candidates and instead “discovers” stella. he has to be definitively hired by leo, and he had to produce viable prospects. he had to find a husband for ruth k. and regain his wife’s confidence. he had to secure leo’s rabbinical title and then make leo proud of himself.

What Salzman must do in order to achieve his goals is that he had to rig things so Leo rejects candidates and instead "discovers" Stella.
Salzman has certain goals that he wanted to accomplish, and he didn't care if he had to do something bad or illegal in order to get what he wants. This is why he decided to cheat and lie to Leo in order to make his dreams come true, at the expense of the people around him.