How should a believer handle a demon-possessed person?

Les explains that he is uncomfortable with exorcism or casting out demons because the Apostle Paul never once gives the Grace Age believer any instructions in dealing with demon possession. The only way he is content about dealing with it is that the person probably needs salvation; if we can present them with the Gospel and see them genuinely born again, then that should take care of their demon possession. He does not set these things in concrete and says if someone thinks he is wrong, that is their privilege. In Samaria, they had the same power Jesus had in His earthly ministry, and unclean spirits came out of many who were possessed, but Paul gives no such instructions for the Grace Age believer.