How to change baby's sleep schedule

Shelby
My one month old still has his days and nights backwards. Every night he'll go to sleep fine but wakes up around 2am and stays awake until 4 sometimes 5am. The first couple of times he would scream the entire time because we were trying to get him to sleep. Now we will just let him stay awake and talk to him, put him in his swing, or just figure out different things to occupy him until he either falls asleep or is hungry again and then he usually falls asleep. We've almost gotten so used to it that we've adjusted our schedule to his but my husband will be going back to work soon so we can't continue this pattern. Any tips or tricks?