With all due respect, your issue is why I personally do not believe in co-sleeping with baby.  Both of our boys slept in their cribs when we brought them from the hospital (the cribs were in the room with us) & then our oldest son (he's 4 now) transistioned to his own bed when he was old enough to get in & out on his own.  Your child is used to the warmth and comfort with mom & dad.  Of course he doesn't want to give that up!  But all good things have to come to an end.

What worked for us is that you will need to bring a chair and a storybook in his room, then read a story to him.  Then wait until he falls asleep.  Sometimes it may take 10- 15 minutes for him to be in full sleep mode. Then ease out of the room.  If he cries, come into the room, cuddle him but do not bring him into your bedroom.  It's what he wants.  Just sit there with him by the bedside until he falls asleep.  You and your husband may have to take turns.  Gradually move the chair out of the room until it's out all of the way.  This may take a week or two, but he will fall asleep on his own.  You may also need to get a night-light for the room, so he won't be too anxious.  This is what worked for my son.  And please consider not co-sleeping with your second child, lest you have the same problem all over again.  You will not be considered bad parents if you choose not to co-sleep & the child will not suffer any emotional detachment. Children need to be able to fall asleep on their own.

When my youngest daughter was born, we were so attached to her, We let her sleep in our bed, Well we      (Me and Daddy ) later divorced and Miss M would still sleep with Mommy,Every night! She was my cuddle bunny!  However Mommy later in life got a new hubby and new hubby didnt want to share the bed!  So he rigged something up and we gentle got her trained to sleep in her own room all by her big girl self in her Big Girl bed!  This is what we did...........we rigged up a fishing line from our bed to the dresser with a  bell on the end of it, the bell laid on the foot of our bed on my side, she always came to my side of the bed, now with bell and line rigged up to dresser,  when she approached the foot of the bed her nightie would make the bell go to the floor causing me to wake up but not so loud to scare her and I would simply take her back to her bed and tell her she was a big girl now and could sleep all by her self cause the bell she heard were the angels watching over her! it Took 3 nights and then it worked and she never returned to our bed at night time she was a brave and Big girl!!

To this day I still miss cuddling with her! So it is harder on the Mommy then it is The Child!! LOL

Good Luck!