I would recommend trying to get him to take his daytime naps in the cot in his own room to begin with, and once he's used to the surroundings you can begin to think about the transition to night-time sleeping.
We co-slept until about 7 months but found it was resulting in us getting no sleep as he is a very wriggly baby and could easily wake us up every 40 minutes.
It took us a long time to get him into his cot properly, but hell it was worth it.
It was gradual but he hasn't been in with us whatsoever for a good few weeks now (and even before that it was only for an hour or so in the morning) - he's now almost 11 months.
Initially what I did was do the dinner, bath, feed, bed routine (putting him down at about 7-half 7). I never ever let him fall asleep while feeding though. DS has a dummy so that was definitely helpful.
I put him down. Went out the room for no more than a minute (I don't believe in CC), then came back in and patted his back/shushed him/sang to him until he'd calmed down. Then would leave the room again and if he wasn't settled I'd go back in after another minute and repeat the procedure until he settled.
If he really wasn't for settling at all I'd pick him up and give him a cuddle and start again afterwards.
I would say from starting that routine to having him fully settled into it took around 2 months. It was hard not to give up and take him into bed, but I'm so glad we persevered.
Now I have a dream of a baby at nighttime (and believe me he was a nightmare a few months ago).
Now he has his bath, sometimes has a feed, sometimes not, goes down in his cot and I leave the room. 9 times out of 10 he falls asleep straight away and most nights he will sleep through until we wake him up in the morning!
Co-sleeping in the early months is lovely, however IME (although granted it won't be like this for everyone) it becomes a bit of a nightmare with night feeds and wriggly babies.
Sorry that was so long, but hope it was helpful.