O.C.
Actually it's fairly easy. My daughter is almost five months and I was having the same problem. So, I started to give her a bath right before It was bed time. (She goes to bed at about 8.) She also gets a bottle right before bed time and then I either lay her in her crib or rock her to sleep. And if that doesn't work also try A baby lotion made for Nighttime. My daughter enjoys the Johnson and Johnson lotion with Lavender, it sooths her and puts her right to sleep. Good luck, and I hope that lil man is good for you.
O.