Fairly easy. It's mostly a conversation with the manager about your background. They're looking for good personality fits for the team position they're looking to fill. You will interview with the team supervisor and (if necessary) a manager.
They'll ask you basic questions, and no financial service background is necessary though familiarity certainly helps.
If you're offered a job and accept, it is contingent upon a criminal background check since you work with a lot of sensitive financial information. That can take a couple weeks to complete. If you pass background, they'll set a start date for you to come aboard.