4 year old! HELP

My son is four years old and I'm 28+5 with a baby girl. We've been living in our house for over a year now. We've been living with my SIL also she just moved out and so now we have two rooms we didn't have with her here. I've fixed up my sons room in everything he loves (Paw patrol) but I cannot get him to sleep in there! With a new baby on the way it's a must to get him in his own room! He sleeps in my bed. Any suggestions on how to get him to adjust? I've done everything from buying a cool nightlight putting in a TV. Help!!!