L.V.
Role play during the day---Have him get his jammies on, brush his teeth, say his prayers, get clothes out for tomorrow, etc.(whatever his normal bedtime routine is). Then pick out 3 books for you to read to him. Tell him after the books you are going to pretend it is night time and he is to stay in bed "all night". You put him to bed lights out or nightlight (normal routine). Leave the room for several minutes. Then come back in all excited (after he has stayed in bed) and say "You did it! You stayed in bed all night! Now you can pick 2 books to read (or a game or fav breakfast" or whatever motivates him). Do exactly the same at bedtime. This can take up to 2 weeks to become a habit---it only took us 3 nights. You can have him pick out what the "reward" will be--books, game, breakfast the night before. If he doesn't stay in his bed at nighttime, the next morning you say, "How sad that you didn't stay in bed all night. I guess we can't read your 2 books, (eat fav breakfast, or play fav game), but tonight we will try again!" (Keep smiling and speak pleasantly---this is something you want him to want to do on the next try because it is so pleasant.) Good luck and remember you want to build your relationship not put a rift between it!!