The things that helped me the most weren't necessarily keeping the baby awake, it was what we did that was different. During the day, talk to him, sing to him, have lots of noises etc. When you change the diaper play with his toes, tell him what you are doing. But during the night keep it dark and quiet. If you need light keep it dim. If you have to change his diaper, or feed him do it as fast as possible with no stimulation. Just do the job and get him back to sleep as quickly as possible. He will soon learn that it is more fun to be awake during the day because you interact with him and at night your aren't any fun. Congratulations and good luck.