Help getting 13 month old to sleep in his cot

I have a co-sleeping (from birth), boobie addict who I NEED to get to sleep in his cot. It has gotten to the point that my husband sleeps in the nursery and me and DS sleep in our bed! I need to do this as our marriage is suffering :(
He still has 4-6 BF's a night. He is fed to sleep then back to sleep. I don't think he needs this many feeds but has them because he can. He still feeds about 6 times during the day too.
He is very much a mum's boy and I am very nervous about how we are going to go getting him to sleep in his own room but the time has come and I need to do it.
I need advice. I have been able to get him to sleep in his cot in the past by patting his back but I've only ever done it for day sleeps. How do I resettle him in the cot? Do i start offering water instead of the breast?

Argghhhhh! I'm so nervous! I dont think I'm truly ready to do this but I know it's for the best..

Thanks in advance xx